TipTap editor, version history, search, attachments — and a cleanup

The app is meant to run in daily private use now, so this pass was mostly
about the ways it could quietly lose data.

Reliability and security:
- the server no longer invents a JWT_SECRET or ENCRYPTION_KEY when one is
  missing; it refuses to start. The old fallback silently made every stored
  note unreadable after a restart.
- notes are encrypted with AES-256-GCM (v2:); existing CBC bodies still read.
- login is rate limited and compares against a dummy hash when the user does
  not exist, so timing does not reveal who is registered.
- a server response issued before a local save is never adopted. This had
  already eaten drawing strokes and note links; sync.hasPendingWrites() now
  guards every path that takes a body from the server.

Editor and features:
- TipTap replaces the contenteditable editor: tables, task lists, and links
  to other notes and notebooks, with a backlinks bar on the target.
- content format v2 ({v:2,doc}); v1 {html,tasks} bodies migrate on open.
- version history: the state before each write is snapshotted, coalesced
  into 5-minute windows, 50 versions or 90 days per note.
- full-text search runs in the client, because the server cannot read
  encrypted bodies and a server index would defeat the encryption.
- image attachments are stored by SHA-256 and deduplicated; the client
  fetches them authenticated and caches the blob, so they work offline.
- drawings are vector strokes in a fixed 1200x1600 page space and now look
  the same on every screen (0.0-0.2% deviation across four widths).
- login is by username; existing email accounts migrate automatically.

Operations:
- data lives on host bind mounts, not Docker volumes, so Proxmox Backup
  covers it. Back up .env with it — without ENCRYPTION_KEY the dump is
  unreadable.

Structure:
- NoteApp.jsx is gone. App.jsx now holds only where the user is; note data,
  search, layout, history and drag each live behind a hook, and the four
  panes are stateless.
- the whole data layer is TypeScript, with 81 unit tests concentrated on
  the places that have actually broken.
- fixed along the way: the browser back button had a dead press, because
  restoring a history entry pushed a duplicate one.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,8 @@
+node_modules/
+dist/
+.env
+.env.*
+!.env.example
+backend/data/
+backend/uploads/
+/data/

backend/server.js

@@ -35,8 +35,36 @@ const http = require("http");
 
 /* ─────────── Config ─────────── */
 const PORT = process.env.PORT || 4000;
-const JWT_SECRET = process.env.JWT_SECRET || "change-me-in-production-" + crypto.randomBytes(16).toString("hex");
+
-const ENCRYPTION_KEY = process.env.ENCRYPTION_KEY || crypto.randomBytes(32).toString("hex");
+/* Secrets must be supplied. They used to fall back to a fresh random value,
+ * which meant a restart without them silently made every stored note
+ * undecryptable — the data was still there, just lost forever. Refuse to boot
+ * instead, and say exactly how to generate what is missing. */
+function requireSecret(name, { hexBytes } = {}) {
+  const v = process.env[name];
+  if (!v) {
+    const how = hexBytes ? `openssl rand -hex ${hexBytes}` : "openssl rand -base64 32";
+    console.error(`\n  ✖ ${name} is not set. Refusing to start.`);
+    console.error(`    Generate one with:  ${how}`);
+    console.error(`    Then put it in .env or pass it as an environment variable.\n`);
+    process.exit(1);
+  }
+  if (hexBytes && !new RegExp(`^[0-9a-fA-F]{${hexBytes * 2}}$`).test(v)) {
+    console.error(`\n  ✖ ${name} must be ${hexBytes * 2} hex characters (${hexBytes} bytes).`);
+    console.error(`    Generate one with:  openssl rand -hex ${hexBytes}\n`);
+    process.exit(1);
+  }
+  return v;
+}
+const JWT_SECRET = requireSecret("JWT_SECRET");
+const ENCRYPTION_KEY = requireSecret("ENCRYPTION_KEY", { hexBytes: 32 });
+const ENCRYPTION_KEY_BUF = Buffer.from(ENCRYPTION_KEY, "hex");
+
+// Which origins may call the API. Same-origin deployments (nginx in front) need
+// none; set a comma-separated list only if you serve the UI from another host.
+const ALLOWED_ORIGINS = (process.env.ALLOWED_ORIGINS || "")
+  .split(",").map((s) => s.trim()).filter(Boolean);
+
 const DATA_DIR = path.join(__dirname, "data");
 const UPLOAD_DIR = path.join(__dirname, "uploads");
 if (!fs.existsSync(DATA_DIR)) fs.mkdirSync(DATA_DIR, { recursive: true });
@@ -50,7 +78,7 @@ db.pragma("foreign_keys = ON");
 db.exec(`
   CREATE TABLE IF NOT EXISTS users (
     id TEXT PRIMARY KEY,
-    email TEXT UNIQUE NOT NULL,
+    username TEXT NOT NULL UNIQUE COLLATE NOCASE,
     password_hash TEXT NOT NULL,
     display_name TEXT,
     created_at TEXT DEFAULT (datetime('now')),
@@ -110,30 +138,128 @@ db.exec(`
     last_sync TEXT DEFAULT (datetime('now'))
   );
 
+  -- Which note references which. Note bodies are encrypted, so the server
+  -- cannot derive this itself; the client sends the link list when it saves.
+  CREATE TABLE IF NOT EXISTS note_links (
+    source_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+    target_id TEXT NOT NULL,
+    target_kind TEXT NOT NULL DEFAULT 'note',
+    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    created_at TEXT DEFAULT (datetime('now')),
+    PRIMARY KEY (source_id, target_id, target_kind)
+  );
+
+  -- Past states of a note, so an accidental overwrite can be undone after the
+  -- fact. Content is encrypted here exactly as it is in the notes table.
+  CREATE TABLE IF NOT EXISTS note_versions (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    note_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    title TEXT,
+    content_encrypted BLOB,
+    drawing_strokes BLOB,
+    device_id TEXT,
+    reason TEXT,
+    created_at TEXT DEFAULT (datetime('now'))
+  );
+
+  -- Binary blobs referenced from note bodies. Stored on disk under a content
+  -- hash, so the same image pasted into ten notes is kept once.
+  CREATE TABLE IF NOT EXISTS attachments (
+    id TEXT PRIMARY KEY,
+    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    sha256 TEXT NOT NULL,
+    mime TEXT NOT NULL,
+    size INTEGER NOT NULL,
+    filename TEXT,
+    created_at TEXT DEFAULT (datetime('now'))
+  );
+
   CREATE INDEX IF NOT EXISTS idx_notes_user ON notes(user_id);
+  CREATE UNIQUE INDEX IF NOT EXISTS idx_attachments_owner_hash ON attachments(user_id, sha256);
+  CREATE INDEX IF NOT EXISTS idx_note_versions ON note_versions(note_id, id DESC);
   CREATE INDEX IF NOT EXISTS idx_notes_notebook ON notes(notebook_id);
   CREATE INDEX IF NOT EXISTS idx_notebooks_user ON notebooks(user_id);
   CREATE INDEX IF NOT EXISTS idx_sync_user ON sync_log(user_id, timestamp);
+  CREATE INDEX IF NOT EXISTS idx_note_links_target ON note_links(user_id, target_id);
+  CREATE INDEX IF NOT EXISTS idx_note_links_source ON note_links(source_id);
 `);
 
+/* ─────────── Migrations ─────────── */
+const tableColumns = (t) => db.prepare(`PRAGMA table_info(${t})`).all().map((c) => c.name);
+
+const USERNAME_RE = /^[a-zA-Z0-9._-]{3,32}$/;
+function normalizeUsername(raw) {
+  const v = String(raw ?? "").trim();
+  return USERNAME_RE.test(v) ? v : null;
+}
+
+// Login used to be e-mail based. Rebuild the table with a username column and
+// derive each existing user's username from the local part of their address.
+(function migrateEmailToUsername() {
+  const cols = tableColumns("users");
+  if (!cols.includes("email")) return;
+
+  db.pragma("foreign_keys = OFF");
+  db.transaction(() => {
+    db.exec(`
+      CREATE TABLE users_migrated (
+        id TEXT PRIMARY KEY,
+        username TEXT NOT NULL UNIQUE COLLATE NOCASE,
+        password_hash TEXT NOT NULL,
+        display_name TEXT,
+        created_at TEXT DEFAULT (datetime('now')),
+        updated_at TEXT DEFAULT (datetime('now'))
+      );
+    `);
+    const insert = db.prepare(
+      "INSERT INTO users_migrated (id, username, password_hash, display_name, created_at, updated_at) VALUES (?, ?, ?, ?, ?, ?)"
+    );
+    const taken = new Set();
+    for (const u of db.prepare("SELECT * FROM users").all()) {
+      const seed = String(u.email || u.display_name || "user").split("@")[0];
+      const base = (seed.replace(/[^a-zA-Z0-9._-]/g, "").slice(0, 32) || "user").padEnd(3, "0");
+      let name = base;
+      for (let i = 2; taken.has(name.toLowerCase()); i++) name = `${base.slice(0, 30)}${i}`;
+      taken.add(name.toLowerCase());
+      insert.run(u.id, name, u.password_hash, u.display_name || name, u.created_at, u.updated_at);
+      console.log(`  ↪ migrated login: ${u.email} → username "${name}"`);
+    }
+    db.exec("DROP TABLE users; ALTER TABLE users_migrated RENAME TO users;");
+  })();
+  db.pragma("foreign_keys = ON");
+  console.log("  ✅ users table migrated from e-mail to username login");
+})();
+
+// Drawings are stored as resolution-independent vector strokes. The legacy
+// raster path (drawing_data_path) stays readable for notes drawn before this.
+if (!tableColumns("notes").includes("drawing_strokes")) {
+  db.exec("ALTER TABLE notes ADD COLUMN drawing_strokes BLOB");
+}
+
 /* ─────────── Encryption helpers ─────────── */
+/* AES-256-GCM. CBC gave confidentiality but no integrity — a flipped bit in the
+ * ciphertext decrypted to garbage instead of failing loudly. GCM authenticates,
+ * so tampering and corruption are detected. Records written before this are
+ * still CBC and stay readable; they re-encrypt as GCM on their next write. */
 function encrypt(text) {
-  const iv = crypto.randomBytes(16);
+  const iv = crypto.randomBytes(12);
-  const key = Buffer.from(ENCRYPTION_KEY, "hex");
+  const cipher = crypto.createCipheriv("aes-256-gcm", ENCRYPTION_KEY_BUF, iv);
-  const cipher = crypto.createCipheriv("aes-256-cbc", key, iv);
+  const enc = Buffer.concat([cipher.update(String(text), "utf8"), cipher.final()]);
-  let encrypted = cipher.update(text, "utf8", "hex");
+  return `v2:${iv.toString("hex")}:${cipher.getAuthTag().toString("hex")}:${enc.toString("hex")}`;
-  encrypted += cipher.final("hex");
-  return iv.toString("hex") + ":" + encrypted;
 }
 
 function decrypt(data) {
-  const [ivHex, encryptedHex] = data.split(":");
+  const s = String(data);
-  const iv = Buffer.from(ivHex, "hex");
+  if (s.startsWith("v2:")) {
-  const key = Buffer.from(ENCRYPTION_KEY, "hex");
+    const [, ivHex, tagHex, encHex] = s.split(":");
-  const decipher = crypto.createDecipheriv("aes-256-cbc", key, iv);
+    const decipher = crypto.createDecipheriv("aes-256-gcm", ENCRYPTION_KEY_BUF, Buffer.from(ivHex, "hex"));
-  let decrypted = decipher.update(encryptedHex, "hex", "utf8");
+    decipher.setAuthTag(Buffer.from(tagHex, "hex"));
-  decrypted += decipher.final("utf8");
+    return decipher.update(encHex, "hex", "utf8") + decipher.final("utf8");
-  return decrypted;
+  }
+  const [ivHex, encryptedHex] = s.split(":"); // legacy AES-256-CBC
+  const decipher = crypto.createDecipheriv("aes-256-cbc", ENCRYPTION_KEY_BUF, Buffer.from(ivHex, "hex"));
+  return decipher.update(encryptedHex, "hex", "utf8") + decipher.final("utf8");
 }
 
 function detectImageMime(buffer, filePath = "") {
@@ -188,9 +314,44 @@ function authMiddleware(req, res, next) {
 
 /* ─────────── Express app ─────────── */
 const app = express();
+app.set("trust proxy", 1); // nginx sits in front; needed for real client IPs
 app.use(helmet());
-app.use(cors());
+app.use(cors(ALLOWED_ORIGINS.length ? { origin: ALLOWED_ORIGINS } : { origin: false }));
-app.use(express.json({ limit: "50mb" }));
+app.use(express.json({ limit: "25mb" }));
+
+/* Password checks are deliberately slow, which makes them both a brute-force
+ * defence and a denial-of-service lever. Cap attempts per username+IP. */
+const RATE_WINDOW_MS = 15 * 60 * 1000;
+const RATE_MAX_ATTEMPTS = 10;
+const loginAttempts = new Map(); // key -> { count, resetAt }
+
+function rateLimitLogin(req, res, next) {
+  const key = `${req.ip}|${String(req.body?.username ?? "").toLowerCase()}`;
+  const now = Date.now();
+  const entry = loginAttempts.get(key);
+  if (!entry || now > entry.resetAt) {
+    loginAttempts.set(key, { count: 1, resetAt: now + RATE_WINDOW_MS });
+    return next();
+  }
+  if (entry.count >= RATE_MAX_ATTEMPTS) {
+    const retryAfter = Math.ceil((entry.resetAt - now) / 1000);
+    res.set("Retry-After", String(retryAfter));
+    return res.status(429).json({ error: "Too many attempts. Try again later.", retryAfter });
+  }
+  entry.count++;
+  next();
+}
+const clearLoginAttempts = (req) => {
+  loginAttempts.delete(`${req.ip}|${String(req.body?.username ?? "").toLowerCase()}`);
+};
+setInterval(() => {
+  const now = Date.now();
+  for (const [k, v] of loginAttempts) if (now > v.resetAt) loginAttempts.delete(k);
+}, RATE_WINDOW_MS).unref();
+
+// A dummy hash keeps "no such user" and "wrong password" equally slow, so the
+// response time does not reveal which usernames exist.
+const DUMMY_HASH = bcrypt.hashSync("not-a-real-password", 12);
 
 const upload = multer({
   dest: UPLOAD_DIR,
@@ -202,66 +363,88 @@ const upload = multer({
 });
 
 /* ─── Auth routes ─── */
-app.post("/api/auth/register", (req, res) => {
+app.post("/api/auth/register", async (req, res, next) => {
-  const { email, password, displayName } = req.body;
+  try {
-  if (!email || !password) return res.status(400).json({ error: "Email and password required" });
+    const { username, password, displayName } = req.body;
+    const name = normalizeUsername(username);
+    if (!name || !password) return res.status(400).json({ error: "Username and password required" });
+    if (String(password).length < 6) return res.status(400).json({ error: "Password must be at least 6 characters" });
 
-  const existing = db.prepare("SELECT id FROM users WHERE email = ?").get(email);
+    const existing = db.prepare("SELECT id FROM users WHERE username = ?").get(name);
-  if (existing) return res.status(409).json({ error: "Email already registered" });
+    if (existing) return res.status(409).json({ error: "Username already taken" });
 
-  const id = uuid();
+    const id = uuid();
-  const hash = bcrypt.hashSync(password, 12);
+    const hash = await bcrypt.hash(password, 12);
-  db.prepare("INSERT INTO users (id, email, password_hash, display_name) VALUES (?, ?, ?, ?)").run(id, email, hash, displayName || email.split("@")[0]);
+    try {
+      db.prepare("INSERT INTO users (id, username, password_hash, display_name) VALUES (?, ?, ?, ?)").run(id, name, hash, displayName || name);
+    } catch (err) {
+      // Someone claimed the name between the check and the insert.
+      if (String(err.message).includes("UNIQUE")) return res.status(409).json({ error: "Username already taken" });
+      throw err;
+    }
 
-  const token = jwt.sign({ userId: id }, JWT_SECRET, { expiresIn: "30d" });
+    const token = jwt.sign({ userId: id }, JWT_SECRET, { expiresIn: "30d" });
-  res.json({ token, user: { id, email, displayName: displayName || email.split("@")[0] } });
+    res.json({ token, user: { id, username: name, displayName: displayName || name } });
+  } catch (err) { next(err); }
 });
 
-app.post("/api/auth/login", (req, res) => {
+app.post("/api/auth/login", rateLimitLogin, async (req, res, next) => {
-  const { email, password } = req.body;
+  try {
-  const user = db.prepare("SELECT * FROM users WHERE email = ?").get(email);
+    const { username, password } = req.body;
-  if (!user || !bcrypt.compareSync(password, user.password_hash)) {
+    const name = String(username ?? "").trim();
-    return res.status(401).json({ error: "Invalid credentials" });
+    const user = name ? db.prepare("SELECT * FROM users WHERE username = ?").get(name) : null;
-  }
+    // Always run a comparison so timing does not leak whether the user exists.
-  const token = jwt.sign({ userId: user.id }, JWT_SECRET, { expiresIn: "30d" });
+    const ok = await bcrypt.compare(String(password ?? ""), user ? user.password_hash : DUMMY_HASH);
-  res.json({ token, user: { id: user.id, email: user.email, displayName: user.display_name } });
+    if (!user || !ok) return res.status(401).json({ error: "Invalid credentials" });
+
+    clearLoginAttempts(req);
+    const token = jwt.sign({ userId: user.id }, JWT_SECRET, { expiresIn: "30d" });
+    res.json({ token, user: { id: user.id, username: user.username, displayName: user.display_name } });
+  } catch (err) { next(err); }
 });
 
 /* ─── Auth profile routes ─── */
 app.get("/api/auth/me", authMiddleware, (req, res) => {
-  const user = db.prepare("SELECT id, email, display_name FROM users WHERE id = ?").get(req.userId);
+  const user = db.prepare("SELECT id, username, display_name FROM users WHERE id = ?").get(req.userId);
   if (!user) return res.status(404).json({ error: "User not found" });
-  res.json({ id: user.id, email: user.email, displayName: user.display_name });
+  res.json({ id: user.id, username: user.username, displayName: user.display_name });
 });
 
 app.put("/api/auth/profile", authMiddleware, (req, res) => {
   const { displayName } = req.body;
   if (!displayName || !displayName.trim()) return res.status(400).json({ error: "Display name required" });
   db.prepare("UPDATE users SET display_name = ?, updated_at = datetime('now') WHERE id = ?").run(displayName.trim(), req.userId);
-  const user = db.prepare("SELECT id, email, display_name FROM users WHERE id = ?").get(req.userId);
+  const user = db.prepare("SELECT id, username, display_name FROM users WHERE id = ?").get(req.userId);
-  res.json({ id: user.id, email: user.email, displayName: user.display_name });
+  res.json({ id: user.id, username: user.username, displayName: user.display_name });
 });
 
-app.put("/api/auth/email", authMiddleware, (req, res) => {
+app.put("/api/auth/username", authMiddleware, async (req, res, next) => {
-  const { newEmail, password } = req.body;
+  try {
-  if (!newEmail || !password) return res.status(400).json({ error: "Email and password required" });
+  const { newUsername, password } = req.body;
+  const name = normalizeUsername(newUsername);
+  if (!name || !password) return res.status(400).json({ error: "Username and password required" });
   const user = db.prepare("SELECT * FROM users WHERE id = ?").get(req.userId);
-  if (!bcrypt.compareSync(password, user.password_hash)) return res.status(401).json({ error: "Wrong password" });
+  if (!user) return res.status(404).json({ error: "User not found" });
-  const exists = db.prepare("SELECT id FROM users WHERE email = ? AND id != ?").get(newEmail, req.userId);
+  if (!(await bcrypt.compare(String(password), user.password_hash))) return res.status(401).json({ error: "Wrong password" });
-  if (exists) return res.status(409).json({ error: "Email already in use" });
+  const exists = db.prepare("SELECT id FROM users WHERE username = ? AND id != ?").get(name, req.userId);
-  db.prepare("UPDATE users SET email = ?, updated_at = datetime('now') WHERE id = ?").run(newEmail, req.userId);
+  if (exists) return res.status(409).json({ error: "Username already taken" });
-  res.json({ id: user.id, email: newEmail, displayName: user.display_name });
+  db.prepare("UPDATE users SET username = ?, updated_at = datetime('now') WHERE id = ?").run(name, req.userId);
+  res.json({ id: user.id, username: name, displayName: user.display_name });
+  } catch (err) { next(err); }
 });
 
-app.put("/api/auth/password", authMiddleware, (req, res) => {
+app.put("/api/auth/password", authMiddleware, async (req, res, next) => {
-  const { currentPassword, newPassword } = req.body;
+  try {
-  if (!currentPassword || !newPassword) return res.status(400).json({ error: "Both passwords required" });
+    const { currentPassword, newPassword } = req.body;
-  if (newPassword.length < 6) return res.status(400).json({ error: "Password must be at least 6 characters" });
+    if (!currentPassword || !newPassword) return res.status(400).json({ error: "Both passwords required" });
-  const user = db.prepare("SELECT * FROM users WHERE id = ?").get(req.userId);
+    if (String(newPassword).length < 6) return res.status(400).json({ error: "Password must be at least 6 characters" });
-  if (!bcrypt.compareSync(currentPassword, user.password_hash)) return res.status(401).json({ error: "Current password is wrong" });
+    const user = db.prepare("SELECT * FROM users WHERE id = ?").get(req.userId);
-  const hash = bcrypt.hashSync(newPassword, 12);
+    if (!user) return res.status(404).json({ error: "User not found" });
-  db.prepare("UPDATE users SET password_hash = ?, updated_at = datetime('now') WHERE id = ?").run(hash, req.userId);
+    if (!(await bcrypt.compare(String(currentPassword), user.password_hash))) return res.status(401).json({ error: "Current password is wrong" });
-  res.json({ success: true });
+    const hash = await bcrypt.hash(String(newPassword), 12);
+    db.prepare("UPDATE users SET password_hash = ?, updated_at = datetime('now') WHERE id = ?").run(hash, req.userId);
+    res.json({ success: true });
+  } catch (err) { next(err); }
 });
 
 /* ─── Notebook routes ─── */
@@ -301,6 +484,61 @@ app.delete("/api/notebooks/:id", authMiddleware, (req, res) => {
   res.json({ success: true });
 });
 
+/* ─────────── Version history ───────────
+ *
+ * A snapshot records what a note looked like *before* a write, so the previous
+ * state is always recoverable.
+ *
+ * Saves arrive roughly once per second while typing, so snapshotting every one
+ * would be useless noise. Instead they coalesce: within the window below, the
+ * existing newest version already represents "before this editing session".
+ * A write that shrinks a note sharply bypasses the window, because that is
+ * exactly the case worth being able to undo. */
+const num = (name, fallback) => {
+  const v = Number(process.env[name]);
+  return Number.isFinite(v) && v > 0 ? v : fallback;
+};
+const VERSION_COALESCE_MS = num("VERSION_COALESCE_MINUTES", 5) * 60 * 1000;
+const MAX_VERSIONS_PER_NOTE = num("MAX_VERSIONS_PER_NOTE", 50);
+const VERSION_RETENTION_DAYS = num("VERSION_RETENTION_DAYS", 90);
+
+const sqliteTimeToMs = (t) => (t ? Date.parse(`${String(t).replace(" ", "T")}Z`) : 0);
+
+function pruneNoteVersions(noteId) {
+  db.prepare(`
+    DELETE FROM note_versions
+    WHERE note_id = ? AND id NOT IN (
+      SELECT id FROM note_versions WHERE note_id = ? ORDER BY id DESC LIMIT ?
+    )`).run(noteId, noteId, MAX_VERSIONS_PER_NOTE);
+}
+
+function snapshotNote(userId, noteId, deviceId, { force = false, reason = "edit" } = {}) {
+  const note = db.prepare(
+    "SELECT title, content_encrypted, drawing_strokes FROM notes WHERE id = ? AND user_id = ?"
+  ).get(noteId, userId);
+  if (!note) return;
+  // An empty note has nothing worth going back to.
+  if (!note.content_encrypted && !note.drawing_strokes) return;
+
+  if (!force) {
+    const last = db.prepare("SELECT created_at FROM note_versions WHERE note_id = ? ORDER BY id DESC LIMIT 1").get(noteId);
+    if (last && Date.now() - sqliteTimeToMs(last.created_at) < VERSION_COALESCE_MS) return;
+  }
+
+  db.prepare(`INSERT INTO note_versions (note_id, user_id, title, content_encrypted, drawing_strokes, device_id, reason)
+    VALUES (?, ?, ?, ?, ?, ?, ?)`)
+    .run(noteId, userId, note.title, note.content_encrypted, note.drawing_strokes, deviceId, reason);
+  pruneNoteVersions(noteId);
+}
+
+/* Ciphertext length tracks plaintext length closely enough to spot a write that
+ * throws most of a note away, without decrypting to find out. */
+function isBigShrink(previous, next) {
+  const before = previous ? previous.length : 0;
+  const after = next ? next.length : 0;
+  return before > 200 && after < before * 0.5;
+}
+
 /* ─── Note routes ─── */
 app.get("/api/notes", authMiddleware, (req, res) => {
   const notes = db.prepare("SELECT id, user_id, notebook_id, type, title, starred, tags, sort_order, created_at, updated_at, version, vector_clock FROM notes WHERE user_id = ? AND deleted_at IS NULL ORDER BY updated_at DESC").all(req.userId);
@@ -316,17 +554,33 @@ app.get("/api/notes/:id", authMiddleware, (req, res) => {
   const note = db.prepare("SELECT * FROM notes WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
   if (!note) return res.status(404).json({ error: "Not found" });
 
-  // Decrypt content
+  /* A failed decrypt used to be reported as empty content. The client then
+   * treated the note as blank and the next edit overwrote the real text — a
+   * read error turned into permanent data loss. Fail the request instead, so
+   * the client keeps showing its local copy. */
   if (note.content_encrypted) {
     try {
       note.content = decrypt(note.content_encrypted.toString());
-    } catch {
+    } catch (err) {
-      note.content = "";
+      console.error(`[decrypt] note ${note.id} content unreadable:`, err.message);
+      return res.status(500).json({ error: "Note content could not be decrypted", id: note.id });
     }
   }
   delete note.content_encrypted;
 
-  // Read drawing data from file if exists
+  // Vector strokes are the source of truth for drawings.
+  note.drawingStrokes = null;
+  if (note.drawing_strokes) {
+    try {
+      note.drawingStrokes = JSON.parse(decrypt(note.drawing_strokes.toString()));
+    } catch (err) {
+      console.error(`[decrypt] note ${note.id} strokes unreadable:`, err.message);
+      return res.status(500).json({ error: "Note drawing could not be decrypted", id: note.id });
+    }
+  }
+  delete note.drawing_strokes;
+
+  // Legacy raster drawing — only for notes created before vector strokes existed.
   if (note.drawing_data_path && fs.existsSync(note.drawing_data_path)) {
     try {
       const raw = fs.readFileSync(note.drawing_data_path);
@@ -359,8 +613,24 @@ app.post("/api/notes", authMiddleware, (req, res) => {
   res.json({ id });
 });
 
+/* Replaces a note's outgoing links. Called whenever its body is saved. */
+const MAX_LINKS_PER_NOTE = 500;
+const replaceNoteLinks = db.transaction((userId, sourceId, links) => {
+  db.prepare("DELETE FROM note_links WHERE source_id = ?").run(sourceId);
+  const insert = db.prepare(
+    "INSERT OR IGNORE INTO note_links (source_id, target_id, target_kind, user_id) VALUES (?, ?, ?, ?)"
+  );
+  for (const link of links.slice(0, MAX_LINKS_PER_NOTE)) {
+    const targetId = typeof link === "string" ? link : link?.id;
+    const kind = (typeof link === "object" && link?.kind) === "notebook" ? "notebook" : "note";
+    if (typeof targetId === "string" && targetId && targetId !== sourceId) {
+      insert.run(sourceId, targetId, kind, userId);
+    }
+  }
+});
+
 app.put("/api/notes/:id", authMiddleware, (req, res) => {
-  const { title, content, notebookId, starred, tags, vectorClock } = req.body;
+  const { title, content, notebookId, starred, tags, vectorClock, links } = req.body;
   const note = db.prepare("SELECT * FROM notes WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
   if (!note) return res.status(404).json({ error: "Not found" });
 
@@ -381,6 +651,15 @@ app.put("/api/notes/:id", authMiddleware, (req, res) => {
   const encContent = content ? encrypt(content) : note.content_encrypted;
   const newClock = { ...mergeVectorClocks(serverClock, clientClock), [req.deviceId]: (serverClock[req.deviceId] || 0) + 1 };
 
+  // Keep the state we are about to replace.
+  if (content !== undefined) {
+    const shrank = isBigShrink(note.content_encrypted, encContent);
+    snapshotNote(req.userId, req.params.id, req.deviceId, {
+      force: shrank,
+      reason: shrank ? "large-deletion" : "edit",
+    });
+  }
+
   db.prepare(`UPDATE notes SET
     title = COALESCE(?, title),
     content_encrypted = COALESCE(?, content_encrypted),
@@ -394,10 +673,106 @@ app.put("/api/notes/:id", authMiddleware, (req, res) => {
     WHERE id = ?`)
     .run(title, encContent, notebookId, starred !== undefined ? (starred ? 1 : 0) : null, tags ? JSON.stringify(tags) : null, JSON.stringify(newClock), req.deviceId, req.params.id);
 
+  if (Array.isArray(links)) replaceNoteLinks(req.userId, req.params.id, links);
+
   broadcastToUser(req.userId, { type: "note_updated", data: { id: req.params.id, title } }, req.deviceId);
   res.json({ success: true, vectorClock: newClock });
 });
 
+/* ─── Version history ─── */
+app.get("/api/notes/:id/versions", authMiddleware, (req, res) => {
+  const note = db.prepare("SELECT id FROM notes WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
+  if (!note) return res.status(404).json({ error: "Not found" });
+  // Sizes only — sending every past body would be a large, mostly unread payload.
+  const rows = db.prepare(`
+    SELECT id, title, device_id, reason, created_at,
+           LENGTH(content_encrypted) AS content_size,
+           drawing_strokes IS NOT NULL AS has_drawing
+    FROM note_versions WHERE note_id = ? ORDER BY id DESC
+  `).all(req.params.id);
+  res.json(rows.map((r) => ({ ...r, has_drawing: !!r.has_drawing })));
+});
+
+app.get("/api/notes/:id/versions/:versionId", authMiddleware, (req, res) => {
+  const v = db.prepare("SELECT * FROM note_versions WHERE id = ? AND note_id = ? AND user_id = ?")
+    .get(req.params.versionId, req.params.id, req.userId);
+  if (!v) return res.status(404).json({ error: "Not found" });
+
+  const out = { id: v.id, title: v.title, created_at: v.created_at, device_id: v.device_id, reason: v.reason };
+  try {
+    out.content = v.content_encrypted ? decrypt(v.content_encrypted.toString()) : "";
+    out.drawingStrokes = v.drawing_strokes ? JSON.parse(decrypt(v.drawing_strokes.toString())) : null;
+  } catch (err) {
+    console.error(`[decrypt] version ${v.id} unreadable:`, err.message);
+    return res.status(500).json({ error: "This version could not be decrypted" });
+  }
+  res.json(out);
+});
+
+/* Restoring is itself an edit, so the state being replaced is snapshotted first
+ * — restoring the wrong version is never a one-way door. */
+app.post("/api/notes/:id/versions/:versionId/restore", authMiddleware, (req, res) => {
+  const note = db.prepare("SELECT * FROM notes WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
+  if (!note) return res.status(404).json({ error: "Not found" });
+  const v = db.prepare("SELECT * FROM note_versions WHERE id = ? AND note_id = ? AND user_id = ?")
+    .get(req.params.versionId, req.params.id, req.userId);
+  if (!v) return res.status(404).json({ error: "Version not found" });
+
+  snapshotNote(req.userId, req.params.id, req.deviceId, { force: true, reason: "before-restore" });
+
+  db.prepare(`UPDATE notes SET content_encrypted = ?, drawing_strokes = ?,
+      updated_at = datetime('now'), version = version + 1, device_id = ? WHERE id = ?`)
+    .run(v.content_encrypted, v.drawing_strokes, req.deviceId, req.params.id);
+
+  // Links live in the restored body, so the index has to follow it back.
+  let links = [];
+  try {
+    if (v.content_encrypted) {
+      const doc = JSON.parse(decrypt(v.content_encrypted.toString()))?.doc;
+      const found = new Set();
+      (function walk(n) {
+        if (!n) return;
+        if (n.type === "noteLink" && n.attrs?.noteId) found.add(n.attrs.noteId);
+        if (Array.isArray(n.content)) n.content.forEach(walk);
+      })(doc);
+      links = [...found];
+    }
+  } catch { /* a v1 body has no links to recover */ }
+  replaceNoteLinks(req.userId, req.params.id, links);
+
+  db.prepare("INSERT INTO sync_log (user_id, entity_type, entity_id, action, payload, device_id) VALUES (?, 'note', ?, 'update', ?, ?)")
+    .run(req.userId, req.params.id, JSON.stringify({ restored: v.id }), req.deviceId);
+  broadcastToUser(req.userId, { type: "note_updated", data: { id: req.params.id, restored: true } }, req.deviceId);
+
+  res.json({ success: true, restoredFrom: v.created_at });
+});
+
+/* Notes that reference this one. Trashed sources are excluded — a backlink from
+ * something in the bin is noise. */
+app.get("/api/notes/:id/backlinks", authMiddleware, (req, res) => {
+  const rows = db.prepare(`
+    SELECT n.id, n.title, n.notebook_id, n.updated_at, nb.name AS notebook_name
+    FROM note_links l
+    JOIN notes n ON n.id = l.source_id
+    LEFT JOIN notebooks nb ON nb.id = n.notebook_id
+    WHERE l.target_id = ? AND l.user_id = ? AND n.deleted_at IS NULL
+    ORDER BY n.updated_at DESC
+  `).all(req.params.id, req.userId);
+  res.json(rows);
+});
+
+/* Every link in one round trip, so the client can render backlink counts in a
+ * list without asking per note. */
+app.get("/api/links", authMiddleware, (req, res) => {
+  const rows = db.prepare(`
+    SELECT l.source_id, l.target_id, l.target_kind
+    FROM note_links l
+    JOIN notes n ON n.id = l.source_id
+    WHERE l.user_id = ? AND n.deleted_at IS NULL
+  `).all(req.userId);
+  res.json(rows);
+});
+
 /* ─── Trash batch endpoint (MUST be before :id routes) ─── */
 app.delete("/api/notes/trash/empty", authMiddleware, (req, res) => {
   db.prepare("DELETE FROM notes WHERE user_id = ? AND deleted_at IS NOT NULL").run(req.userId);
@@ -425,30 +800,55 @@ app.delete("/api/notes/:id/permanent", authMiddleware, (req, res) => {
 });
 
 /* ─── Drawing data route ─── */
+const MAX_STROKES = 20000;
+
 app.put("/api/notes/:id/drawing", authMiddleware, (req, res) => {
-  const { drawingData } = req.body;
+  const { drawingStrokes, drawingData } = req.body;
   const note = db.prepare("SELECT id FROM notes WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
   if (!note) return res.status(404).json({ error: "Not found" });
 
-  if (!drawingData || typeof drawingData !== "string") return res.status(400).json({ error: "drawingData required" });
+  if (drawingStrokes !== undefined) {
-  const m = drawingData.match(/^data:(image\/(?:png|jpeg|jpg|webp));base64,(.+)$/);
+    // Vector strokes in the note's canonical coordinate space — the current format.
-  if (!m) return res.status(400).json({ error: "Invalid drawing format" });
+    if (drawingStrokes !== null) {
-  const mime = m[1];
+      if (typeof drawingStrokes !== "object" || !Array.isArray(drawingStrokes.strokes))
-  const ext = mime === "image/png" ? "png" : mime === "image/webp" ? "webp" : "jpg";
+        return res.status(400).json({ error: "Invalid strokes format" });
-  const base64Data = m[2];
+      if (drawingStrokes.strokes.length > MAX_STROKES)
-  const filePath = path.join(UPLOAD_DIR, `drawing_${req.params.id}.${ext}`);
+        return res.status(413).json({ error: "Too many strokes" });
-
-  // Remove older file variants from previous format writes.
-  for (const oldExt of ["png", "jpg", "jpeg", "webp"]) {
-    const oldPath = path.join(UPLOAD_DIR, `drawing_${req.params.id}.${oldExt}`);
-    if (oldPath !== filePath && fs.existsSync(oldPath)) {
-      try { fs.unlinkSync(oldPath); } catch {}
     }
+    const empty = !drawingStrokes || drawingStrokes.strokes.length === 0;
+    const previous = db.prepare("SELECT drawing_strokes FROM notes WHERE id = ?").get(req.params.id);
+    // Clearing a drawing is always worth being able to undo.
+    snapshotNote(req.userId, req.params.id, req.deviceId, {
+      force: empty && !!previous?.drawing_strokes,
+      reason: empty ? "drawing-cleared" : "drawing",
+    });
+    // A note's legacy raster is left untouched — it renders underneath the strokes
+    // on the client, so migrating an old drawing never loses anything.
+    db.prepare("UPDATE notes SET drawing_strokes = ?, updated_at = datetime('now'), version = version + 1, device_id = ? WHERE id = ?")
+      .run(empty ? null : Buffer.from(encrypt(JSON.stringify(drawingStrokes))), req.deviceId, req.params.id);
+  } else {
+    // Legacy raster path, kept so older clients keep working.
+    if (!drawingData || typeof drawingData !== "string") return res.status(400).json({ error: "drawingStrokes or drawingData required" });
+    const m = drawingData.match(/^data:(image\/(?:png|jpeg|jpg|webp));base64,(.+)$/);
+    if (!m) return res.status(400).json({ error: "Invalid drawing format" });
+    const mime = m[1];
+    const ext = mime === "image/png" ? "png" : mime === "image/webp" ? "webp" : "jpg";
+    const base64Data = m[2];
+    const filePath = path.join(UPLOAD_DIR, `drawing_${req.params.id}.${ext}`);
+
+    // Remove older file variants from previous format writes.
+    for (const oldExt of ["png", "jpg", "jpeg", "webp"]) {
+      const oldPath = path.join(UPLOAD_DIR, `drawing_${req.params.id}.${oldExt}`);
+      if (oldPath !== filePath && fs.existsSync(oldPath)) {
+        try { fs.unlinkSync(oldPath); } catch {}
+      }
+    }
+    fs.writeFileSync(filePath, Buffer.from(base64Data, "base64"));
+
+    db.prepare("UPDATE notes SET drawing_data_path = ?, updated_at = datetime('now'), version = version + 1, device_id = ? WHERE id = ?")
+      .run(filePath, req.deviceId, req.params.id);
   }
-  fs.writeFileSync(filePath, Buffer.from(base64Data, "base64"));
 
-  db.prepare("UPDATE notes SET drawing_data_path = ?, updated_at = datetime('now'), version = version + 1, device_id = ? WHERE id = ?")
-    .run(filePath, req.deviceId, req.params.id);
   db.prepare("INSERT INTO sync_log (user_id, entity_type, entity_id, action, payload, device_id) VALUES (?, 'note', ?, 'update', ?, ?)")
     .run(req.userId, req.params.id, JSON.stringify({ drawingUpdated: true }), req.deviceId);
   broadcastToUser(req.userId, { type: "note_updated", data: { id: req.params.id, drawingUpdated: true } }, req.deviceId);
@@ -456,6 +856,69 @@ app.put("/api/notes/:id/drawing", authMiddleware, (req, res) => {
   res.json({ success: true });
 });
 
+/* ─── Attachments ───
+ *
+ * Images used to be inlined into the note body as base64 data URIs: a few
+ * screenshots turned a note into megabytes that were re-encrypted and re-sent on
+ * every keystroke. They are now separate blobs the body only references.
+ *
+ * Files are named by SHA-256 of their bytes, so the same image pasted into
+ * several notes is stored once. */
+const ATTACHMENT_DIR = path.join(UPLOAD_DIR, "attachments");
+if (!fs.existsSync(ATTACHMENT_DIR)) fs.mkdirSync(ATTACHMENT_DIR, { recursive: true });
+
+const ALLOWED_ATTACHMENT_MIME = new Set(["image/png", "image/jpeg", "image/webp", "image/gif", "image/avif"]);
+const MAX_ATTACHMENT_BYTES = 15 * 1024 * 1024;
+
+app.post("/api/attachments", authMiddleware, (req, res) => {
+  const { data, filename } = req.body || {};
+  if (typeof data !== "string") return res.status(400).json({ error: "data required" });
+
+  const m = data.match(/^data:([a-z0-9.+/-]+);base64,(.+)$/i);
+  if (!m) return res.status(400).json({ error: "Expected a base64 data URL" });
+  const mime = m[1].toLowerCase();
+  if (!ALLOWED_ATTACHMENT_MIME.has(mime)) return res.status(415).json({ error: `Unsupported type: ${mime}` });
+
+  const buf = Buffer.from(m[2], "base64");
+  if (buf.length === 0) return res.status(400).json({ error: "Empty file" });
+  if (buf.length > MAX_ATTACHMENT_BYTES) return res.status(413).json({ error: "File too large" });
+
+  // Trust the bytes, not the declared type.
+  const sniffed = detectImageMime(buf);
+  if (mime !== "image/gif" && mime !== "image/avif" && sniffed !== mime) {
+    return res.status(415).json({ error: "File content does not match its type" });
+  }
+
+  const sha256 = crypto.createHash("sha256").update(buf).digest("hex");
+  const existing = db.prepare("SELECT id, mime, size FROM attachments WHERE user_id = ? AND sha256 = ?").get(req.userId, sha256);
+  if (existing) return res.json({ id: existing.id, mime: existing.mime, size: existing.size, deduplicated: true });
+
+  const filePath = path.join(ATTACHMENT_DIR, sha256);
+  if (!fs.existsSync(filePath)) fs.writeFileSync(filePath, buf);
+
+  const id = uuid();
+  db.prepare("INSERT INTO attachments (id, user_id, sha256, mime, size, filename) VALUES (?, ?, ?, ?, ?, ?)")
+    .run(id, req.userId, sha256, mime, buf.length, typeof filename === "string" ? filename.slice(0, 200) : null);
+
+  res.json({ id, mime, size: buf.length, deduplicated: false });
+});
+
+app.get("/api/attachments/:id", authMiddleware, (req, res) => {
+  const a = db.prepare("SELECT * FROM attachments WHERE id = ? AND user_id = ?").get(req.params.id, req.userId);
+  if (!a) return res.status(404).json({ error: "Not found" });
+
+  // The hash comes from our own database, never from the request, so this path
+  // cannot be steered outside the attachment directory.
+  const filePath = path.join(ATTACHMENT_DIR, a.sha256);
+  if (!fs.existsSync(filePath)) return res.status(404).json({ error: "File missing" });
+
+  res.setHeader("Content-Type", a.mime);
+  res.setHeader("Content-Length", a.size);
+  res.setHeader("Cache-Control", "private, max-age=31536000, immutable"); // content-addressed: never changes
+  res.setHeader("X-Content-Type-Options", "nosniff");
+  fs.createReadStream(filePath).pipe(res);
+});
+
 /* ─── PDF upload route ─── */
 app.post("/api/notes/pdf", authMiddleware, upload.single("pdf"), (req, res) => {
   if (!req.file) return res.status(400).json({ error: "No file uploaded" });
@@ -528,42 +991,68 @@ const server = http.createServer(app);
 const wss = new WebSocketServer({ server, path: "/ws" });
 const userConnections = new Map(); // userId -> Set<ws>
 
-wss.on("connection", (ws, req) => {
+const AUTH_GRACE_MS = 10000;
-  let userId = null;
+const HEARTBEAT_MS = 30000;
+
+wss.on("connection", (ws) => {
+  ws._userId = null;
+  ws._alive = true;
+  ws.on("pong", () => { ws._alive = true; });
+
+  // Drop sockets that connect and never authenticate.
+  const authTimer = setTimeout(() => {
+    if (!ws._userId) ws.close(4001, "auth timeout");
+  }, AUTH_GRACE_MS);
 
   ws.on("message", (data) => {
     try {
       const msg = JSON.parse(data);
-      if (msg.type === "auth") {
+      if (msg.type !== "auth") return;
-        const payload = jwt.verify(msg.token, JWT_SECRET);
+      const payload = jwt.verify(msg.token, JWT_SECRET);
-        userId = payload.userId;
+      ws._userId = payload.userId;
-        const deviceId = msg.deviceId || "unknown";
+      ws._deviceId = msg.deviceId || "unknown";
+      clearTimeout(authTimer);
 
-        if (!userConnections.has(userId)) userConnections.set(userId, new Map());
+      // A Set, not a Map keyed by device: two tabs on one machine share a
-        userConnections.get(userId).set(deviceId, ws);
+      // device id, and keying by it meant the second tab silently replaced the
-        ws._deviceId = deviceId;
+      // first and the first stopped receiving updates.
+      if (!userConnections.has(ws._userId)) userConnections.set(ws._userId, new Set());
+      userConnections.get(ws._userId).add(ws);
 
-        ws.send(JSON.stringify({ type: "auth_ok" }));
+      ws.send(JSON.stringify({ type: "auth_ok" }));
-      }
     } catch {
-      ws.send(JSON.stringify({ type: "error", message: "Invalid message" }));
+      try { ws.send(JSON.stringify({ type: "error", message: "Invalid message" })); } catch {}
     }
   });
 
   ws.on("close", () => {
-    if (userId && userConnections.has(userId)) {
+    clearTimeout(authTimer);
-      userConnections.get(userId).delete(ws._deviceId);
+    const set = ws._userId && userConnections.get(ws._userId);
-      if (userConnections.get(userId).size === 0) userConnections.delete(userId);
+    if (!set) return;
-    }
+    set.delete(ws);
+    if (set.size === 0) userConnections.delete(ws._userId);
   });
+  ws.on("error", () => { try { ws.terminate(); } catch {} });
 });
 
+// Reap sockets that stopped answering — otherwise half-open connections from
+// sleeping phones accumulate forever.
+const heartbeat = setInterval(() => {
+  for (const ws of wss.clients) {
+    if (!ws._alive) { ws.terminate(); continue; }
+    ws._alive = false;
+    try { ws.ping(); } catch {}
+  }
+}, HEARTBEAT_MS);
+heartbeat.unref();
+
 function broadcastToUser(userId, message, excludeDeviceId) {
-  if (!userConnections.has(userId)) return;
+  const conns = userConnections.get(userId);
-  const connections = userConnections.get(userId);
+  if (!conns) return;
-  for (const [deviceId, ws] of connections) {
+  const payload = JSON.stringify(message);
-    if (deviceId !== excludeDeviceId && ws.readyState === 1) {
+  for (const ws of conns) {
-      ws.send(JSON.stringify(message));
+    if (ws._deviceId !== excludeDeviceId && ws.readyState === 1) {
+      try { ws.send(payload); } catch {}
     }
   }
 }
@@ -573,10 +1062,91 @@ app.get("/api/health", (req, res) => {
   res.json({ status: "ok", version: "1.0.0", uptime: process.uptime() });
 });
 
+/* ─── Error handling ─── */
+app.use((req, res) => res.status(404).json({ error: "Not found" }));
+
+// Without this, a throw inside a route hangs the request until the client times
+// out, and the stack trace goes to the client in Express' default handler.
+app.use((err, req, res, next) => { // eslint-disable-line no-unused-vars
+  console.error("[error]", req.method, req.path, err);
+  if (res.headersSent) return;
+  if (err?.type === "entity.too.large") return res.status(413).json({ error: "Payload too large" });
+  res.status(500).json({ error: "Internal server error" });
+});
+
+process.on("unhandledRejection", (err) => console.error("[unhandledRejection]", err));
+process.on("uncaughtException", (err) => console.error("[uncaughtException]", err));
+
+/* ─── Housekeeping ─── */
+// sync_log is append-only and grew without bound; every note edit added a row.
+const SYNC_LOG_RETENTION_DAYS = 30;
+function pruneSyncLog() {
+  try {
+    const r = db.prepare(`DELETE FROM sync_log WHERE timestamp < datetime('now', '-${SYNC_LOG_RETENTION_DAYS} days')`).run();
+    if (r.changes) console.log(`  🧹 pruned ${r.changes} sync_log rows older than ${SYNC_LOG_RETENTION_DAYS} days`);
+  } catch (err) { console.error("[prune] failed:", err.message); }
+}
+
+/* Per-note count is capped on write; this only clears out versions of notes
+ * that stopped being edited long ago. */
+function pruneOldVersions() {
+  try {
+    const r = db.prepare(`DELETE FROM note_versions WHERE created_at < datetime('now', '-${VERSION_RETENTION_DAYS} days')`).run();
+    if (r.changes) console.log(`  🧹 pruned ${r.changes} note versions older than ${VERSION_RETENTION_DAYS} days`);
+  } catch (err) { console.error("[prune] failed:", err.message); }
+}
+
+/* Attachment rows cascade away with their owner, but the files they point at do
+ * not. The database is authoritative: a blob nobody has a row for is garbage.
+ *
+ * Only files that have sat untouched for an hour are considered, so an upload
+ * in flight — written to disk just before its row is inserted — is never hit. */
+const ORPHAN_GRACE_MS = 60 * 60 * 1000;
+function pruneOrphanAttachments() {
+  try {
+    if (!fs.existsSync(ATTACHMENT_DIR)) return;
+    const referenced = new Set(db.prepare("SELECT sha256 FROM attachments").all().map((r) => r.sha256));
+    let removed = 0;
+    for (const name of fs.readdirSync(ATTACHMENT_DIR)) {
+      if (referenced.has(name)) continue;
+      const full = path.join(ATTACHMENT_DIR, name);
+      try {
+        if (Date.now() - fs.statSync(full).mtimeMs < ORPHAN_GRACE_MS) continue;
+        fs.unlinkSync(full);
+        removed++;
+      } catch { /* leave anything we cannot inspect alone */ }
+    }
+    if (removed) console.log(`  🧹 removed ${removed} orphaned attachment file(s)`);
+  } catch (err) { console.error("[prune] attachments failed:", err.message); }
+}
+
+const housekeeping = () => { pruneSyncLog(); pruneOldVersions(); pruneOrphanAttachments(); };
+housekeeping();
+setInterval(housekeeping, 24 * 60 * 60 * 1000).unref();
+
 /* ─── Start server ─── */
 server.listen(PORT, () => {
   console.log(`\n  ✏️  InkNote Server running on http://localhost:${PORT}`);
   console.log(`  📡 WebSocket available at ws://localhost:${PORT}/ws`);
-  console.log(`  🔒 JWT Secret: ${JWT_SECRET.slice(0, 12)}...`);
+  console.log(`  💾 Database: ${path.join(DATA_DIR, "inknote.db")}`);
-  console.log(`  💾 Database: ${path.join(DATA_DIR, "inknote.db")}\n`);
+  console.log(`  🌐 CORS: ${ALLOWED_ORIGINS.length ? ALLOWED_ORIGINS.join(", ") : "same-origin only"}\n`);
 });
+
+/* ─── Graceful shutdown ─── */
+let shuttingDown = false;
+function shutdown(signal) {
+  if (shuttingDown) return;
+  shuttingDown = true;
+  console.log(`\n  ${signal} received — shutting down...`);
+  clearInterval(heartbeat);
+  for (const ws of wss.clients) { try { ws.close(1001, "server shutting down"); } catch {} }
+  server.close(() => {
+    try { db.close(); } catch (err) { console.error("[shutdown] db.close:", err.message); }
+    console.log("  ✅ closed cleanly\n");
+    process.exit(0);
+  });
+  // Don't hang forever on a stuck connection.
+  setTimeout(() => { try { db.close(); } catch {} process.exit(1); }, 10000).unref();
+}
+process.on("SIGTERM", () => shutdown("SIGTERM"));
+process.on("SIGINT", () => shutdown("SIGINT"));

build.sh

@@ -2,7 +2,7 @@
 set -e
 
 REGISTRY="gitea.honeyy.duckdns.org"
-OWNER="docker"
+OWNER="${GITEA_OWNER:-marc}"
 TAG="${1:-latest}"
 
 FRONTEND_IMAGE="${REGISTRY}/${OWNER}/inknote-web:${TAG}"

docker-compose.dev.yml

@@ -0,0 +1,73 @@
+# ─────────────────────────────────────────────
+# InkNote — lokales Test-Setup (baut aus dem Quellcode)
+#
+# Prod-nah (nginx + gebautes Bundle) auf :3000
+#   docker compose -f docker-compose.dev.yml up -d --build
+#
+# Mit Hot-Reload-Dev-Server auf :5173 zusätzlich
+#   docker compose -f docker-compose.dev.yml --profile dev up -d --build
+#
+#   docker compose -f docker-compose.dev.yml logs -f
+#   docker compose -f docker-compose.dev.yml down
+#
+# Secrets kommen aus .env (nicht committen!)
+# Daten liegen unter ${INKNOTE_DATA_DIR:-./data} auf dem Host.
+# ─────────────────────────────────────────────
+
+services:
+  inknote-server:
+    build:
+      context: ./backend
+      dockerfile: Dockerfile
+    container_name: inknote-server-dev
+    restart: unless-stopped
+    environment:
+      - PORT=4000
+      - JWT_SECRET=${JWT_SECRET}
+      - ENCRYPTION_KEY=${ENCRYPTION_KEY}
+      - NODE_ENV=development
+    # Bind mounts, not named volumes: the data sits in a plain directory on the
+    # Docker host where the host's own backup picks it up.
+    user: "${INKNOTE_UID:-1000}:${INKNOTE_GID:-1000}"
+    volumes:
+      - ${INKNOTE_DATA_DIR:-./data}/db:/app/data
+      - ${INKNOTE_DATA_DIR:-./data}/uploads:/app/uploads
+    healthcheck:
+      test: ["CMD", "wget", "-qO-", "http://localhost:4000/api/health"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 10s
+
+  inknote-web:
+    build:
+      context: ./frontend
+      dockerfile: dockerfile
+    container_name: inknote-web-dev
+    restart: unless-stopped
+    ports:
+      - "3000:80"
+    depends_on:
+      inknote-server:
+        condition: service_healthy
+
+  # Vite mit Hot-Reload — nur mit "--profile dev"
+  inknote-vite:
+    image: node:20-alpine
+    container_name: inknote-vite-dev
+    profiles: ["dev"]
+    working_dir: /app
+    command: sh -c "npm install && npm run dev"
+    environment:
+      - VITE_API_TARGET=http://inknote-server:4000
+    volumes:
+      - ./frontend:/app
+      - inknote-dev-node-modules:/app/node_modules
+    ports:
+      - "5173:5173"
+    depends_on:
+      inknote-server:
+        condition: service_healthy
+
+volumes:
+  inknote-dev-node-modules:

docker-compose.yml

@@ -5,9 +5,15 @@ version: "3.8"
 # Pull images from Gitea container registry
 #
 # Usage:
+#   mkdir -p /srv/inknote/db /srv/inknote/uploads
+#   chown -R 1000:1000 /srv/inknote
 #   docker login gitea.honeyy.duckdns.org
-#   docker-compose pull
+#   docker compose pull
-#   docker-compose up -d
+#   docker compose up -d
+#
+# Data lives under INKNOTE_DATA_DIR (default /srv/inknote) on the host.
+# Back that path up together with the .env holding ENCRYPTION_KEY — the
+# database is encrypted and is unreadable without that key.
 # ─────────────────────────────────────────────
 
 services:
@@ -20,9 +26,13 @@ services:
       - JWT_SECRET=${JWT_SECRET}
       - ENCRYPTION_KEY=${ENCRYPTION_KEY}
       - NODE_ENV=production
+    # Bind mounts, not named volumes: the data sits in a plain directory on the
+    # Docker host, so whatever backs up the host also backs up InkNote.
+    # Create it first:  mkdir -p /srv/inknote/{db,uploads} && chown -R 1000:1000 /srv/inknote
+    user: "${INKNOTE_UID:-1000}:${INKNOTE_GID:-1000}"
     volumes:
-      - inknote-data:/app/data
+      - ${INKNOTE_DATA_DIR:-/srv/inknote}/db:/app/data
-      - inknote-uploads:/app/uploads
+      - ${INKNOTE_DATA_DIR:-/srv/inknote}/uploads:/app/uploads
     healthcheck:
       test: ["CMD", "wget", "-qO-", "http://localhost:4000/api/health"]
       interval: 30s

frontend/.prettierignore

@@ -0,0 +1,3 @@
+dist/
+node_modules/
+package-lock.json

frontend/.prettierrc.json

@@ -0,0 +1,8 @@
+{
+  "printWidth": 110,
+  "singleQuote": false,
+  "semi": true,
+  "trailingComma": "es5",
+  "arrowParens": "always",
+  "bracketSameLine": false
+}

frontend/index.html

@@ -11,7 +11,7 @@
     <meta name="description" content="Write & draw — notes that sync everywhere" />
     <meta name="mobile-web-app-capable" content="yes" />
     <link rel="manifest" href="./manifest.json" />
-    <link rel="apple-touch-icon" href="./icon-192.png" />
+    <link rel="apple-touch-icon" href="./apple-touch-icon.png" />
     <link rel="icon" type="image/png" sizes="192x192" href="./icon-192.png" />
     <link rel="icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>✏️</text></svg>" />
     <title>InkNote</title>

frontend/nginx.conf

@@ -29,8 +29,8 @@ server {
         try_files $uri =404;
     }
 
-    # Icons
+    # Icons (icon-*.png and apple-touch-icon.png)
-    location ~* ^/icon-.*\.png$ {
+    location ~* ^/(icon-.*|apple-touch-icon)\.png$ {
         add_header Cache-Control "public, max-age=86400";
         try_files $uri =404;
     }

frontend/package.json

@@ -6,14 +6,40 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "typecheck": "tsc --noEmit",
+    "format": "prettier --write 'src/**/*.{js,jsx,ts,tsx,css}'"
   },
   "dependencies": {
+    "@tiptap/extension-image": "^2.27.2",
+    "@tiptap/extension-link": "^2.27.2",
+    "@tiptap/extension-placeholder": "^2.27.2",
+    "@tiptap/extension-table": "^2.27.2",
+    "@tiptap/extension-table-cell": "^2.27.2",
+    "@tiptap/extension-table-header": "^2.27.2",
+    "@tiptap/extension-table-row": "^2.27.2",
+    "@tiptap/extension-task-item": "^2.27.2",
+    "@tiptap/extension-task-list": "^2.27.2",
+    "@tiptap/extension-underline": "^2.27.2",
+    "@tiptap/html": "^2.27.2",
+    "@tiptap/pm": "^2.27.2",
+    "@tiptap/react": "^2.27.2",
+    "@tiptap/starter-kit": "^2.27.2",
+    "@tiptap/suggestion": "^2.27.2",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"
   },
   "devDependencies": {
+    "@types/react": "^18.3.31",
+    "@types/react-dom": "^18.3.7",
     "@vitejs/plugin-react": "^4.3.1",
-    "vite": "^5.4.0"
+    "fake-indexeddb": "^6.2.5",
+    "jsdom": "^25.0.1",
+    "prettier": "^3.9.6",
+    "typescript": "^5.9.3",
+    "vite": "^5.4.0",
+    "vitest": "^2.1.9"
   }
 }

frontend/public/manifest.json

@@ -9,7 +9,10 @@
   "background_color": "#0d1117",
   "theme_color": "#0d1117",
   "orientation": "any",
-  "categories": ["productivity", "utilities"],
+  "categories": [
+    "productivity",
+    "utilities"
+  ],
   "icons": [
     {
       "src": "./icon-192.png",
@@ -24,13 +27,13 @@
       "purpose": "any"
     },
     {
-      "src": "./icon-192.png",
+      "src": "./icon-maskable-192.png",
       "sizes": "192x192",
       "type": "image/png",
       "purpose": "maskable"
     },
     {
-      "src": "./icon-512.png",
+      "src": "./icon-maskable-512.png",
       "sizes": "512x512",
       "type": "image/png",
       "purpose": "maskable"

frontend/public/sw.js

@@ -1,4 +1,4 @@
-const CACHE_NAME = 'inknote-v6';
+const CACHE_NAME = 'inknote-v7';
 
 // Install — don't precache, just activate immediately
 self.addEventListener('install', () => {

frontend/src/App.jsx

@@ -0,0 +1,563 @@
+import { useCallback, useEffect, useMemo, useState } from "react";
+
+import * as sync from "./syncEngine";
+import { useNoteData } from "./hooks/useNoteData";
+import { useSearchIndex } from "./hooks/useSearchIndex";
+import { useResponsive } from "./hooks/useResponsive";
+import { usePwaInstall } from "./hooks/usePwaInstall";
+import { useNotebookDnd } from "./hooks/useNotebookDnd";
+import { useNavigationHistory } from "./hooks/useNavigationHistory";
+
+import { COVERS, DEFAULT_FOLDERS } from "./ui/constants.jsx";
+import { I } from "./ui/icons.jsx";
+import { makeTheme, FONT_UI } from "./ui/theme";
+import { ConfirmDialog } from "./ui/ConfirmDialog.jsx";
+import { ContextMenu } from "./ui/ContextMenu.jsx";
+import { EditNotebookModal, CreateNotebookModal } from "./ui/NotebookModals.jsx";
+import { AccountMenu } from "./ui/AccountMenu.jsx";
+import { AuthScreen } from "./ui/AuthScreen.jsx";
+import { Sidebar } from "./ui/Sidebar.jsx";
+import { Dashboard } from "./features/notebooks/Dashboard.jsx";
+import { NoteList } from "./features/notes/NoteList.jsx";
+import { EditorPane } from "./features/notes/EditorPane.jsx";
+import { HistoryModal } from "./features/notes/HistoryModal.jsx";
+import { DrawingLayer } from "./features/drawing/DrawingLayer.jsx";
+import { CANON_W, CANON_H, PREVIEW_DRAWING_W } from "./features/drawing/strokes.js";
+
+/** Views that are not a notebook and therefore cannot hold a new note. */
+const VIRTUAL_FOLDERS = ["all", "starred", "trash", "dashboard"];
+
+const EMPTY_BODY = { content: "", drawingData: null, drawingStrokes: null };
+
+/**
+ * Root of the application.
+ *
+ * Holds the things that describe *where the user is* — the open notebook, the
+ * open note, the search box, whichever dialog is up — and hands the data itself
+ * to `useNoteData`. Rendering is delegated to the three panes below.
+ */
+export default function App() {
+  const [dark, setDark] = useState(true);
+  const [user, setUser] = useState(null);
+  const [loading, setLoading] = useState(true);
+  const [syncStatus, setSyncStatus] = useState("synced");
+
+  const [activeFolder, setActiveFolder] = useState("dashboard");
+  const [activeNote, setActiveNote] = useState(null);
+  const [searchQuery, setSearchQuery] = useState("");
+
+  const [showNewNb, setShowNewNb] = useState(false);
+  const [editingNb, setEditingNb] = useState(null);
+  const [showAccount, setShowAccount] = useState(false);
+  const [historyFor, setHistoryFor] = useState(null);
+  const [ctxMenu, setCtxMenu] = useState(null);
+  const [confirmDialog, setConfirmDialog] = useState(null);
+  // Bumped on a version restore to force a fresh editor on the restored body.
+  const [restoreEpoch, setRestoreEpoch] = useState(0);
+
+  const T = useMemo(() => makeTheme(dark), [dark]);
+  const { isMobile, sidebarOpen, setSidebarOpen, mobileView, setMobileView } = useResponsive();
+  const { canInstall, promptInstall } = usePwaInstall();
+
+  const data = useNoteData(user, activeNote);
+  const { notes, notebooks, noteContents, backlinks } = data;
+  const search = useSearchIndex(user, notes, searchQuery);
+  const dnd = useNotebookDnd(data.reorderNotebooks);
+
+  useEffect(() => sync.onSyncStatus(setSyncStatus), []);
+
+  /* ── Session ── */
+  useEffect(() => {
+    (async () => {
+      try {
+        const u = await sync.restoreSession();
+        if (u) {
+          setUser(u);
+          await data.reload();
+          try {
+            await sync.fullSync();
+            await data.reload();
+          } catch (e) {
+            if (e.message === "AUTH") setUser(null);
+          }
+        }
+      } catch {
+        /* a broken session must not block the app from starting */
+      }
+      setLoading(false);
+    })();
+  }, []);
+
+  const onLogin = async (u) => {
+    setUser(u);
+    try {
+      await sync.fullSync();
+    } catch {
+      /* first sync can fail offline; local data still loads */
+    }
+    await data.reload();
+  };
+
+  const onLogout = async () => {
+    await sync.logout();
+    setUser(null);
+    data.reset();
+    setActiveNote(null);
+    setActiveFolder("dashboard");
+  };
+
+  /* ── Navigation ── */
+  const openFolder = useCallback(
+    (id) => {
+      setActiveFolder(id);
+      setActiveNote(null);
+      if (isMobile) {
+        setSidebarOpen(false);
+        setMobileView("list");
+      }
+    },
+    [isMobile, setSidebarOpen, setMobileView]
+  );
+
+  const openNote = useCallback(
+    (id) => {
+      setActiveNote(id);
+      if (isMobile) setMobileView("editor");
+    },
+    [isMobile, setMobileView]
+  );
+
+  const closeNote = useCallback(() => {
+    setActiveNote(null);
+    if (isMobile) setMobileView("list");
+  }, [isMobile, setMobileView]);
+
+  // Adopts a location the user reached with the browser's back button.
+  const applyNavState = useCallback(
+    (s) => {
+      setActiveFolder(s.folder);
+      setActiveNote(s.note);
+      setMobileView(s.view);
+    },
+    [setMobileView]
+  );
+  useNavigationHistory({ folder: activeFolder, note: activeNote, view: mobileView }, isMobile, applyNavState);
+
+  /* ── Derived note lists ── */
+  const activeNotes = useMemo(() => notes.filter((n) => !n.trashed), [notes]);
+  const trashedNotes = useMemo(() => notes.filter((n) => n.trashed), [notes]);
+  const isTrashView = activeFolder === "trash";
+
+  const filteredNotes = useMemo(() => {
+    let list;
+    if (activeFolder === "trash") list = trashedNotes;
+    else if (activeFolder === "starred") list = activeNotes.filter((n) => n.starred);
+    else if (activeFolder === "all" || activeFolder === "dashboard") list = activeNotes;
+    else list = activeNotes.filter((n) => n.folderId === activeFolder);
+
+    if (searchQuery.trim()) {
+      // A search reads every note's text, so results keep the index's relevance
+      // order instead of being re-sorted by date.
+      if (search.results) {
+        const rank = new Map(search.results.map((h, i) => [h.id, i]));
+        return list.filter((n) => rank.has(n.id)).sort((a, b) => rank.get(a.id) - rank.get(b.id));
+      }
+      // Until the index answers, fall back to matching titles only.
+      const q = searchQuery.toLowerCase();
+      return list.filter((n) => n.title.toLowerCase().includes(q));
+    }
+    return [...list].sort((a, b) => new Date(b.updatedAt) - new Date(a.updatedAt));
+  }, [activeFolder, searchQuery, search.results, activeNotes, trashedNotes]);
+
+  const noteMeta = activeNote ? notes.find((n) => n.id === activeNote) : null;
+  // The editor opens as soon as the metadata is known; the body fills in when
+  // it arrives, rather than blocking on a fetch.
+  const openNoteData = noteMeta ? { ...noteMeta, ...EMPTY_BODY, ...noteContents[activeNote] } : null;
+
+  const folderName = useMemo(() => {
+    const builtIn = DEFAULT_FOLDERS.find((f) => f.id === activeFolder);
+    if (builtIn) return builtIn.name;
+    return notebooks.find((n) => n.id === activeFolder)?.name || "Notes";
+  }, [activeFolder, notebooks]);
+
+  /* ── Note links ── */
+  // Candidates for the @-menu. Notes rank above notebooks, trashed notes never
+  // appear, and the open note cannot link to itself.
+  const searchLinkTargets = useCallback(
+    (query) => {
+      const q = (query || "").toLowerCase().trim();
+      const match = (name) => !q || name.toLowerCase().includes(q);
+      return [
+        ...notes
+          .filter((n) => !n.trashed && n.id !== activeNote && match(n.title || "Untitled"))
+          .slice(0, 8)
+          .map((n) => ({ id: n.id, label: n.title || "Untitled", kind: "note" })),
+        ...notebooks
+          .filter((nb) => match(nb.name))
+          .slice(0, 4)
+          .map((nb) => ({ id: nb.id, label: nb.name, kind: "notebook" })),
+      ];
+    },
+    [notes, notebooks, activeNote]
+  );
+
+  // A link stores the label it had when inserted; this keeps it showing the
+  // target's current title, and returns null once the target is gone.
+  const resolveLinkLabel = useCallback(
+    (id) => {
+      const n = notes.find((x) => x.id === id && !x.trashed);
+      if (n) return n.title || "Untitled";
+      return notebooks.find((x) => x.id === id)?.name ?? null;
+    },
+    [notes, notebooks]
+  );
+
+  const openLinkTarget = useCallback(
+    (id, kind) => {
+      if (kind === "notebook") return openFolder(id);
+      const target = notes.find((n) => n.id === id);
+      if (!target) return;
+      if (target.folderId) setActiveFolder(target.folderId);
+      openNote(id);
+    },
+    [notes, openFolder, openNote]
+  );
+
+  const linkProps = useMemo(
+    () => ({ openLinkTarget, searchLinkTargets, resolveLinkLabel }),
+    [openLinkTarget, searchLinkTargets, resolveLinkLabel]
+  );
+
+  /* ── Actions ── */
+  const createNote = async () => {
+    const folderId = VIRTUAL_FOLDERS.includes(activeFolder) ? notebooks[0]?.id : activeFolder;
+    if (!folderId) return;
+    const note = await data.createNote(folderId);
+    if (activeFolder === "dashboard") setActiveFolder(folderId);
+    openNote(note.id);
+  };
+
+  /** Runs a destructive action behind a confirmation prompt. */
+  const confirm = (dialog) =>
+    setConfirmDialog({
+      ...dialog,
+      onConfirm: async () => {
+        await dialog.onConfirm();
+        setConfirmDialog(null);
+      },
+    });
+
+  const trashNote = (id) =>
+    confirm({
+      title: "Move to Trash",
+      message: `Move "${notes.find((n) => n.id === id)?.title}" to trash?`,
+      confirmLabel: "Move to Trash",
+      onConfirm: async () => {
+        await data.trashNote(id);
+        if (activeNote === id) closeNote();
+      },
+    });
+
+  const restoreNote = async (id) => {
+    await data.restoreNote(id);
+    if (activeNote === id) closeNote();
+  };
+
+  const permanentDeleteNote = (id) =>
+    confirm({
+      title: "Delete Permanently",
+      message: `Permanently delete "${notes.find((n) => n.id === id)?.title}"? This cannot be undone.`,
+      onConfirm: async () => {
+        await data.permanentDeleteNote(id);
+        if (activeNote === id) closeNote();
+      },
+    });
+
+  const emptyTrash = () =>
+    confirm({
+      title: "Empty Trash",
+      message: `Permanently delete all ${trashedNotes.length} trashed notes?`,
+      onConfirm: async () => {
+        await data.emptyTrash();
+        setActiveNote(null);
+      },
+    });
+
+  const createNotebook = async (fields) => {
+    const nb = await data.createNotebook(fields);
+    setShowNewNb(false);
+    setActiveFolder(nb.id);
+  };
+
+  const updateNotebook = async (id, updates) => {
+    await data.updateNotebook(id, updates);
+    setEditingNb(null);
+  };
+
+  const deleteNotebook = (id) => {
+    const nb = notebooks.find((n) => n.id === id);
+    const count = activeNotes.filter((n) => n.folderId === id).length;
+    confirm({
+      title: "Delete Notebook",
+      message: `Delete "${nb?.name}"${count > 0 ? ` and trash its ${count} notes` : ""} permanently?`,
+      onConfirm: async () => {
+        await data.deleteNotebook(id);
+        if (activeFolder === id) setActiveFolder("dashboard");
+      },
+    });
+  };
+
+  /* ── Context menus ── */
+  const notebookContextMenu = (e, nb) => {
+    e.preventDefault();
+    e.stopPropagation();
+    setCtxMenu({
+      x: e.clientX,
+      y: e.clientY,
+      items: [
+        { label: "Edit", icon: I.edit, action: () => setEditingNb(nb) },
+        { divider: true },
+        { label: "Delete Notebook", icon: I.trash, danger: true, action: () => deleteNotebook(nb.id) },
+      ],
+    });
+  };
+
+  /** "Move to..." lists every notebook except the one the note is already in. */
+  const moveSubmenu = (note) => {
+    const targets = notebooks
+      .filter((nb) => nb.id !== note.folderId)
+      .map((nb) => ({
+        label: nb.name,
+        colorDot: COVERS[nb.cover % COVERS.length].bg,
+        action: () => data.moveNote(note.id, nb.id),
+      }));
+    return targets.length > 0 ? [{ label: "Move to...", icon: I.move, submenu: targets }] : [];
+  };
+
+  const noteContextMenu = (e, note) => {
+    e.preventDefault();
+    e.stopPropagation();
+    const items = note.trashed
+      ? [
+          { label: "Restore", icon: I.restore, action: () => restoreNote(note.id) },
+          { divider: true },
+          {
+            label: "Delete Permanently",
+            icon: I.trash,
+            danger: true,
+            action: () => permanentDeleteNote(note.id),
+          },
+        ]
+      : [
+          {
+            label: note.starred ? "Unstar" : "Star",
+            icon: note.starred ? I.starFill : I.star,
+            action: () => data.toggleStar(note.id),
+          },
+          ...moveSubmenu(note),
+          { divider: true },
+          { label: "Move to Trash", icon: I.trash, danger: true, action: () => trashNote(note.id) },
+        ];
+    setCtxMenu({ x: e.clientX, y: e.clientY, items });
+  };
+
+  /* ── Render ── */
+  if (loading)
+    return (
+      <div
+        style={{
+          display: "flex",
+          alignItems: "center",
+          justifyContent: "center",
+          height: "100vh",
+          background: T.bg,
+          color: T.text,
+          fontFamily: FONT_UI,
+          fontSize: 16,
+        }}
+      >
+        Loading...
+      </div>
+    );
+
+  if (!user) return <AuthScreen onLogin={onLogin} dark={dark} />;
+
+  // On a phone the list and the editor take turns; on a desktop both are shown.
+  const showList = !(isMobile && mobileView === "editor" && activeNote);
+  const showEditor = !isMobile || mobileView === "editor";
+
+  return (
+    <div
+      style={{
+        display: "flex",
+        height: "100vh",
+        width: "100vw",
+        overflow: "hidden",
+        background: T.bg,
+        color: T.text,
+        fontFamily: FONT_UI,
+      }}
+    >
+      <style>{`
+        @import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,300;0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400&family=DM+Sans:wght@400;500;600;700&display=swap');
+        *{box-sizing:border-box;margin:0;padding:0}
+        ::-webkit-scrollbar{width:5px}::-webkit-scrollbar-track{background:transparent}
+        ::-webkit-scrollbar-thumb{background:${T.borderLight};border-radius:3px}
+        button:hover{opacity:0.88}
+        input::placeholder{color:${T.faint}}
+        [contenteditable]:empty:before{content:'Start writing...';color:${T.faint};pointer-events:none}
+        [draggable]{user-select:none}
+        @media(max-width:767px){
+          ::-webkit-scrollbar{display:none}
+          body{-webkit-tap-highlight-color:transparent;-webkit-touch-callout:none}
+        }
+      `}</style>
+
+      <Sidebar
+        T={T}
+        dark={dark}
+        onToggleDark={() => setDark(!dark)}
+        isMobile={isMobile}
+        open={sidebarOpen}
+        onClose={() => setSidebarOpen(false)}
+        searchQuery={searchQuery}
+        onSearchChange={setSearchQuery}
+        activeFolder={activeFolder}
+        onSelectFolder={openFolder}
+        notebooks={notebooks}
+        activeNotes={activeNotes}
+        trashedCount={trashedNotes.length}
+        onNewNotebook={() => setShowNewNb(true)}
+        onOpenAccount={() => setShowAccount(true)}
+        onNotebookContextMenu={notebookContextMenu}
+        dnd={dnd}
+        canInstall={canInstall}
+        onInstall={promptInstall}
+        syncStatus={syncStatus}
+        online={sync.isOnline()}
+      />
+
+      {activeFolder === "dashboard" ? (
+        <Dashboard
+          T={T}
+          isMobile={isMobile}
+          notebooks={notebooks}
+          activeNotes={activeNotes}
+          activeFolder={activeFolder}
+          onToggleSidebar={() => setSidebarOpen(!sidebarOpen)}
+          onOpenNotebook={openFolder}
+          onOpenNote={(note) => {
+            setActiveFolder(note.folderId);
+            openNote(note.id);
+          }}
+          onNewNotebook={() => setShowNewNb(true)}
+          onNotebookContextMenu={notebookContextMenu}
+          dnd={dnd}
+        />
+      ) : (
+        <>
+          {showList && (
+            <NoteList
+              T={T}
+              isMobile={isMobile}
+              title={folderName}
+              notes={filteredNotes}
+              activeNote={activeNote}
+              isTrashView={isTrashView}
+              trashedCount={trashedNotes.length}
+              snippetFor={search.snippetFor}
+              onToggleSidebar={() => setSidebarOpen(!sidebarOpen)}
+              onSelectNote={openNote}
+              onNoteContextMenu={noteContextMenu}
+              onCreateNote={createNote}
+              onEmptyTrash={emptyTrash}
+            />
+          )}
+          {showEditor && (
+            <EditorPane
+              T={T}
+              dark={dark}
+              isMobile={isMobile}
+              note={openNoteData}
+              isTrashView={isTrashView}
+              restoreEpoch={restoreEpoch}
+              backlinks={backlinks}
+              linkProps={linkProps}
+              onBack={closeNote}
+              onUpdate={(u) => data.updateNote(activeNote, u)}
+              onToggleStar={() => data.toggleStar(activeNote)}
+              onTrash={() => trashNote(activeNote)}
+              onRestore={() => restoreNote(activeNote)}
+              onPermanentDelete={() => permanentDeleteNote(activeNote)}
+              onOpenHistory={() => setHistoryFor(activeNote)}
+              onCreateNote={createNote}
+            />
+          )}
+        </>
+      )}
+
+      {showNewNb && (
+        <CreateNotebookModal onClose={() => setShowNewNb(false)} onCreate={createNotebook} dark={dark} />
+      )}
+      {editingNb && (
+        <EditNotebookModal
+          notebook={editingNb}
+          onClose={() => setEditingNb(null)}
+          onSave={(u) => updateNotebook(editingNb.id, u)}
+          dark={dark}
+        />
+      )}
+      {showAccount && (
+        <AccountMenu
+          user={user}
+          onClose={() => setShowAccount(false)}
+          onLogout={() => {
+            setShowAccount(false);
+            onLogout();
+          }}
+          onUserUpdate={setUser}
+          dark={dark}
+        />
+      )}
+      {historyFor && (
+        <HistoryModal
+          noteId={historyFor}
+          noteTitle={notes.find((n) => n.id === historyFor)?.title}
+          dark={dark}
+          onClose={() => setHistoryFor(null)}
+          onRestored={(content) => {
+            data.setNoteContent(historyFor, content);
+            setRestoreEpoch((e) => e + 1);
+          }}
+          renderDrawing={(strokes) => (
+            <DrawingLayer
+              strokes={strokes.strokes || []}
+              width={PREVIEW_DRAWING_W}
+              height={Math.round((PREVIEW_DRAWING_W * CANON_H) / CANON_W)}
+              zIndex={1}
+            />
+          )}
+        />
+      )}
+      {confirmDialog && (
+        <ConfirmDialog
+          title={confirmDialog.title}
+          message={confirmDialog.message}
+          confirmLabel={confirmDialog.confirmLabel}
+          onConfirm={confirmDialog.onConfirm}
+          onCancel={() => setConfirmDialog(null)}
+          dark={dark}
+        />
+      )}
+      {ctxMenu && (
+        <ContextMenu
+          x={ctxMenu.x}
+          y={ctxMenu.y}
+          items={ctxMenu.items}
+          onClose={() => setCtxMenu(null)}
+          dark={dark}
+        />
+      )}
+    </div>
+  );
+}

frontend/src/editor/EditorToolbar.jsx

@@ -0,0 +1,342 @@
+import { useEffect, useState } from "react";
+
+/* Icons the main app does not already provide, drawn to match its stroke style. */
+const strokeProps = {
+  width: 15,
+  height: 15,
+  viewBox: "0 0 24 24",
+  fill: "none",
+  stroke: "currentColor",
+  strokeWidth: 2,
+  strokeLinecap: "round",
+  strokeLinejoin: "round",
+};
+
+const TableIcon = () => (
+  <svg {...strokeProps}>
+    <rect x="3" y="3" width="18" height="18" rx="2" />
+    <line x1="3" y1="9" x2="21" y2="9" />
+    <line x1="3" y1="15" x2="21" y2="15" />
+    <line x1="9" y1="3" x2="9" y2="21" />
+  </svg>
+);
+const LinkIcon = () => (
+  <svg {...strokeProps}>
+    <path d="M10 13a5 5 0 0 0 7.5.5l3-3a5 5 0 0 0-7-7l-1.7 1.7" />
+    <path d="M14 11a5 5 0 0 0-7.5-.5l-3 3a5 5 0 0 0 7 7l1.7-1.7" />
+  </svg>
+);
+const QuoteIcon = () => (
+  <svg {...strokeProps}>
+    <path d="M6 17h3l2-4V7H5v6h3z" />
+    <path d="M16 17h3l2-4V7h-6v6h3z" />
+  </svg>
+);
+const CodeIcon = () => (
+  <svg {...strokeProps}>
+    <polyline points="16 18 22 12 16 6" />
+    <polyline points="8 6 2 12 8 18" />
+  </svg>
+);
+const AtIcon = () => (
+  <svg {...strokeProps}>
+    <circle cx="12" cy="12" r="4" />
+    <path d="M16 8v5a3 3 0 0 0 6 0v-1a10 10 0 1 0-3.9 7.9" />
+  </svg>
+);
+
+/**
+ * Formatting controls for the note body.
+ *
+ * Reads its active states straight off the editor, so the buttons reflect the
+ * cursor even when formatting changed by keyboard shortcut.
+ */
+export function EditorToolbar({ editor, T, icons, compact }) {
+  const [, force] = useState(0);
+  const [showTable, setShowTable] = useState(false);
+
+  // ProseMirror state changes do not go through React; subscribe so the active
+  // states stay in sync with the cursor.
+  useEffect(() => {
+    if (!editor) return;
+    const rerender = () => force((n) => n + 1);
+    editor.on("transaction", rerender);
+    editor.on("selectionUpdate", rerender);
+    return () => {
+      editor.off("transaction", rerender);
+      editor.off("selectionUpdate", rerender);
+    };
+  }, [editor]);
+
+  useEffect(() => {
+    if (!showTable) return;
+    const close = (e) => {
+      if (!e.target.closest?.("[data-table-menu]")) setShowTable(false);
+    };
+    document.addEventListener("pointerdown", close);
+    return () => document.removeEventListener("pointerdown", close);
+  }, [showTable]);
+
+  if (!editor) return null;
+
+  const btn = (active) => ({
+    display: "flex",
+    alignItems: "center",
+    justifyContent: "center",
+    width: 30,
+    height: 30,
+    borderRadius: 6,
+    border: "none",
+    cursor: "pointer",
+    background: active ? T.active + "22" : "transparent",
+    color: active ? T.active : T.text,
+    transition: "all .12s",
+    flexShrink: 0,
+  });
+  const divider = (
+    <div style={{ width: 1, height: 22, background: T.border, margin: "0 2px", flexShrink: 0 }} />
+  );
+  const inTable = editor.isActive("table");
+
+  const menuItem = {
+    display: "block",
+    width: "100%",
+    padding: "6px 10px",
+    border: "none",
+    borderRadius: 6,
+    background: "transparent",
+    color: T.text,
+    fontSize: 12,
+    textAlign: "left",
+    cursor: "pointer",
+  };
+
+  const promptLink = () => {
+    const previous = editor.getAttributes("link").href || "";
+    const url = window.prompt("Link URL (leave empty to remove)", previous);
+    if (url === null) return;
+    if (url === "") {
+      editor.chain().focus().extendMarkRange("link").unsetLink().run();
+      return;
+    }
+    if (!/^(https?|mailto):/i.test(url)) {
+      window.alert("Only http(s) and mailto links are allowed.");
+      return;
+    }
+    editor.chain().focus().extendMarkRange("link").setLink({ href: url }).run();
+  };
+
+  return (
+    <>
+      <button
+        style={btn(editor.isActive("bold"))}
+        title="Bold (Ctrl+B)"
+        onClick={() => editor.chain().focus().toggleBold().run()}
+      >
+        {icons.bold}
+      </button>
+      <button
+        style={btn(editor.isActive("italic"))}
+        title="Italic (Ctrl+I)"
+        onClick={() => editor.chain().focus().toggleItalic().run()}
+      >
+        {icons.italic}
+      </button>
+      <button
+        style={btn(editor.isActive("underline"))}
+        title="Underline (Ctrl+U)"
+        onClick={() => editor.chain().focus().toggleUnderline().run()}
+      >
+        {icons.underline}
+      </button>
+      {divider}
+      <button
+        style={btn(editor.isActive("bulletList"))}
+        title="Bullet list"
+        onClick={() => editor.chain().focus().toggleBulletList().run()}
+      >
+        {icons.list}
+      </button>
+      <button
+        style={btn(editor.isActive("orderedList"))}
+        title="Numbered list"
+        onClick={() => editor.chain().focus().toggleOrderedList().run()}
+      >
+        {icons.listOrd}
+      </button>
+      <button
+        style={btn(editor.isActive("taskList"))}
+        title="Task list"
+        onClick={() => editor.chain().focus().toggleTaskList().run()}
+      >
+        {icons.check}
+      </button>
+      {divider}
+
+      {/* Tables */}
+      <div style={{ position: "relative" }} data-table-menu>
+        <button style={btn(inTable || showTable)} title="Table" onClick={() => setShowTable((v) => !v)}>
+          <TableIcon />
+        </button>
+        {showTable && (
+          <div
+            style={{
+              position: "absolute",
+              top: 36,
+              left: 0,
+              minWidth: 190,
+              background: T.toolbar,
+              border: `1px solid ${T.border}`,
+              borderRadius: 12,
+              padding: 6,
+              zIndex: 200,
+              boxShadow: "0 8px 20px rgba(0,0,0,.2)",
+            }}
+          >
+            <button
+              style={menuItem}
+              onClick={() => {
+                editor.chain().focus().insertTable({ rows: 3, cols: 3, withHeaderRow: true }).run();
+                setShowTable(false);
+              }}
+            >
+              Insert 3 × 3 table
+            </button>
+            {inTable && (
+              <>
+                <div style={{ height: 1, background: T.border, margin: "5px 2px" }} />
+                <button style={menuItem} onClick={() => editor.chain().focus().addColumnBefore().run()}>
+                  Add column left
+                </button>
+                <button style={menuItem} onClick={() => editor.chain().focus().addColumnAfter().run()}>
+                  Add column right
+                </button>
+                <button style={menuItem} onClick={() => editor.chain().focus().addRowBefore().run()}>
+                  Add row above
+                </button>
+                <button style={menuItem} onClick={() => editor.chain().focus().addRowAfter().run()}>
+                  Add row below
+                </button>
+                <div style={{ height: 1, background: T.border, margin: "5px 2px" }} />
+                <button style={menuItem} onClick={() => editor.chain().focus().toggleHeaderRow().run()}>
+                  Toggle header row
+                </button>
+                <button style={menuItem} onClick={() => editor.chain().focus().mergeOrSplit().run()}>
+                  Merge / split cells
+                </button>
+                <div style={{ height: 1, background: T.border, margin: "5px 2px" }} />
+                <button
+                  style={{ ...menuItem, color: T.danger || "#e5534b" }}
+                  onClick={() => editor.chain().focus().deleteColumn().run()}
+                >
+                  Delete column
+                </button>
+                <button
+                  style={{ ...menuItem, color: T.danger || "#e5534b" }}
+                  onClick={() => editor.chain().focus().deleteRow().run()}
+                >
+                  Delete row
+                </button>
+                <button
+                  style={{ ...menuItem, color: T.danger || "#e5534b" }}
+                  onClick={() => {
+                    editor.chain().focus().deleteTable().run();
+                    setShowTable(false);
+                  }}
+                >
+                  Delete table
+                </button>
+              </>
+            )}
+          </div>
+        )}
+      </div>
+
+      <button
+        style={btn(false)}
+        title="Link to another note (or type @)"
+        onClick={() => editor.chain().focus().insertContent("@").run()}
+      >
+        <AtIcon />
+      </button>
+      <button style={btn(editor.isActive("link"))} title="Web link" onClick={promptLink}>
+        <LinkIcon />
+      </button>
+
+      {!compact && (
+        <>
+          {divider}
+          <button
+            style={btn(editor.isActive("blockquote"))}
+            title="Quote"
+            onClick={() => editor.chain().focus().toggleBlockquote().run()}
+          >
+            <QuoteIcon />
+          </button>
+          <button
+            style={btn(editor.isActive("codeBlock"))}
+            title="Code block"
+            onClick={() => editor.chain().focus().toggleCodeBlock().run()}
+          >
+            <CodeIcon />
+          </button>
+        </>
+      )}
+
+      {divider}
+      <select
+        value={
+          editor.isActive("heading", { level: 1 })
+            ? "h1"
+            : editor.isActive("heading", { level: 2 })
+              ? "h2"
+              : editor.isActive("heading", { level: 3 })
+                ? "h3"
+                : "p"
+        }
+        onChange={(e) => {
+          const v = e.target.value;
+          if (v === "p") editor.chain().focus().setParagraph().run();
+          else
+            editor
+              .chain()
+              .focus()
+              .toggleHeading({ level: Number(v[1]) })
+              .run();
+        }}
+        style={{
+          border: `1px solid ${T.border}`,
+          borderRadius: 6,
+          padding: "3px 6px",
+          background: T.toolbar,
+          color: T.text,
+          fontSize: 11,
+          cursor: "pointer",
+        }}
+      >
+        <option value="p">Body</option>
+        <option value="h1">H1</option>
+        <option value="h2">H2</option>
+        <option value="h3">H3</option>
+      </select>
+
+      {divider}
+      <button
+        style={{ ...btn(false), opacity: editor.can().undo() ? 1 : 0.35 }}
+        title="Undo"
+        onClick={() => editor.chain().focus().undo().run()}
+      >
+        {icons.undo}
+      </button>
+      <button
+        style={{ ...btn(false), opacity: editor.can().redo() ? 1 : 0.35 }}
+        title="Redo"
+        onClick={() => editor.chain().focus().redo().run()}
+      >
+        {icons.redo}
+      </button>
+    </>
+  );
+}
+
+export default EditorToolbar;

frontend/src/editor/VersionPreview.jsx

@@ -0,0 +1,39 @@
+import { useEffect, useMemo } from "react";
+import { useEditor, EditorContent } from "@tiptap/react";
+
+import { buildExtensions } from "./extensions.js";
+import { parseNoteContent } from "./content";
+import "./editor.css";
+
+/**
+ * Read-only render of a stored note body.
+ *
+ * Uses the same extension set as the real editor, so a past version is shown
+ * with the formatting it actually had — including tables and note links —
+ * rather than a stripped-down approximation.
+ */
+export function VersionPreview({ content, dark }) {
+  const extensions = useMemo(() => buildExtensions(), []);
+
+  const editor = useEditor(
+    {
+      extensions,
+      editable: false,
+      content: parseNoteContent(content, extensions),
+    },
+    []
+  );
+
+  useEffect(() => {
+    if (!editor || editor.isDestroyed) return;
+    editor.commands.setContent(parseNoteContent(content, extensions), false);
+  }, [editor, content, extensions]);
+
+  return (
+    <div className="note-editor" data-theme={dark ? "dark" : "light"}>
+      <EditorContent editor={editor} />
+    </div>
+  );
+}
+
+export default VersionPreview;

frontend/src/editor/attachmentImage.js

@@ -0,0 +1,82 @@
+/**
+ * Images in a note body.
+ *
+ * New images are stored as attachments and the document only keeps their id.
+ * Older notes inlined the bytes as a base64 data URI; those still render, so
+ * nothing written before this change is lost — they simply stay heavy until
+ * re-inserted.
+ */
+
+import Image from "@tiptap/extension-image";
+import { resolveUrl } from "./attachments.js";
+
+export const AttachmentImage = Image.extend({
+  addAttributes() {
+    return {
+      ...this.parent?.(),
+      attachmentId: {
+        default: null,
+        parseHTML: (el) => el.getAttribute("data-attachment"),
+        renderHTML: (attrs) => (attrs.attachmentId ? { "data-attachment": attrs.attachmentId } : {}),
+      },
+      // Preserved from the old inline-style images so their sizing survives.
+      width: {
+        default: null,
+        parseHTML: (el) => el.style?.width || el.getAttribute("width") || null,
+        renderHTML: (attrs) => (attrs.width ? { style: `width: ${attrs.width}` } : {}),
+      },
+    };
+  },
+
+  renderHTML({ HTMLAttributes }) {
+    // A blob URL is meaningless outside this page, so an attachment-backed image
+    // is serialised without a src; the node view supplies one at display time.
+    const attrs = { ...HTMLAttributes };
+    if (attrs["data-attachment"]) delete attrs.src;
+    return ["img", attrs];
+  },
+
+  addNodeView() {
+    return ({ node }) => {
+      const dom = document.createElement("img");
+      dom.className = "note-image";
+      if (node.attrs.alt) dom.alt = node.attrs.alt;
+      if (node.attrs.title) dom.title = node.attrs.title;
+      if (node.attrs.width) dom.style.width = node.attrs.width;
+
+      let currentId = node.attrs.attachmentId;
+
+      const paint = (attrs) => {
+        if (attrs.attachmentId) {
+          dom.dataset.attachment = attrs.attachmentId;
+          resolveUrl(attrs.attachmentId)
+            .then((url) => {
+              if (url) dom.src = url;
+            })
+            .catch(() => {
+              dom.alt = attrs.alt || "Image unavailable";
+              dom.dataset.missing = "true";
+            });
+        } else if (attrs.src) {
+          dom.src = attrs.src; // legacy inline data URI
+        }
+      };
+      paint(node.attrs);
+
+      return {
+        dom,
+        update(updated) {
+          if (updated.type.name !== node.type.name) return false;
+          if (updated.attrs.width !== dom.style.width) dom.style.width = updated.attrs.width || "";
+          if (updated.attrs.attachmentId !== currentId) {
+            currentId = updated.attrs.attachmentId;
+            paint(updated.attrs);
+          }
+          return true;
+        },
+      };
+    };
+  },
+});
+
+export default AttachmentImage;

frontend/src/editor/attachments.js

@@ -0,0 +1,73 @@
+/**
+ * Attachment plumbing for the editor.
+ *
+ * An `<img>` tag cannot carry an Authorization header, so attachment bytes are
+ * fetched with an authenticated request, kept in IndexedDB and handed to the
+ * DOM as a blob URL. That also means images render offline, and each one is
+ * downloaded at most once per device.
+ */
+
+import * as sync from "../syncEngine";
+import * as db from "../offlineStore";
+
+const _urls = new Map(); // attachmentId -> object URL
+const _inflight = new Map(); // attachmentId -> Promise<string>
+
+export const MAX_ATTACHMENT_BYTES = 15 * 1024 * 1024;
+export const ACCEPTED_TYPES = ["image/png", "image/jpeg", "image/webp", "image/gif", "image/avif"];
+
+const readAsDataUrl = (file) =>
+  new Promise((resolve, reject) => {
+    const r = new FileReader();
+    r.onload = () => resolve(r.result);
+    r.onerror = () => reject(r.error || new Error("Could not read file"));
+    r.readAsDataURL(file);
+  });
+
+/** Uploads a pasted or dropped image and returns its attachment id. */
+export async function uploadImage(file) {
+  if (!ACCEPTED_TYPES.includes(file.type))
+    throw new Error(`Unsupported image type: ${file.type || "unknown"}`);
+  if (file.size > MAX_ATTACHMENT_BYTES) throw new Error("Image is larger than 15 MB");
+
+  const dataUrl = await readAsDataUrl(file);
+  const { id } = await sync.uploadAttachment(dataUrl, file.name);
+
+  // Seed the cache from the bytes already in hand — no round trip to display it.
+  try {
+    await db.putAttachmentBlob(id, file);
+  } catch {
+    /* cache is best-effort */
+  }
+  return id;
+}
+
+/** A displayable URL for an attachment, from cache when possible. */
+export function resolveUrl(id) {
+  if (!id) return Promise.resolve(null);
+  const cached = _urls.get(id);
+  if (cached) return Promise.resolve(cached);
+  if (_inflight.has(id)) return _inflight.get(id);
+
+  const job = (async () => {
+    let blob = await db.getAttachmentBlob(id).catch(() => null);
+    if (!blob) {
+      blob = await sync.fetchAttachmentBlob(id);
+      db.putAttachmentBlob(id, blob).catch(() => {});
+    }
+    const url = URL.createObjectURL(blob);
+    _urls.set(id, url);
+    return url;
+  })().finally(() => _inflight.delete(id));
+
+  _inflight.set(id, job);
+  return job;
+}
+
+/* Object URLs live as long as the page does. They are a few dozen bytes of
+ * bookkeeping each and the same image usually reappears as the user moves
+ * between notes, so they are kept rather than revoked per unmount. */
+export function releaseAll() {
+  for (const url of _urls.values()) URL.revokeObjectURL(url);
+  _urls.clear();
+}

frontend/src/editor/content.test.ts

@@ -0,0 +1,183 @@
+import { describe, it, expect } from "vitest";
+
+import { parseNoteContent, serializeNoteContent, extractNoteLinks, docToText } from "./content";
+import { parsingExtensions } from "./extensions.js";
+
+const parse = (raw: unknown) => parseNoteContent(raw, parsingExtensions);
+
+/** Collects every node type in a document, for asserting on structure. */
+const typesIn = (doc: any): string[] => {
+  const out: string[] = [];
+  (function walk(n: any) {
+    if (!n) return;
+    if (n.type) out.push(n.type);
+    if (Array.isArray(n.content)) n.content.forEach(walk);
+  })(doc);
+  return out;
+};
+
+describe("parseNoteContent", () => {
+  it("returns an empty document for empty input", () => {
+    for (const empty of [null, undefined, ""]) {
+      expect(parse(empty)).toEqual({ type: "doc", content: [{ type: "paragraph" }] });
+    }
+  });
+
+  it("passes a v2 document through untouched", () => {
+    const doc = { type: "doc", content: [{ type: "paragraph", content: [{ type: "text", text: "hi" }] }] };
+    expect(parse(JSON.stringify({ v: 2, doc }))).toEqual(doc);
+  });
+
+  describe("v1 migration", () => {
+    it("keeps headings, marks and lists", () => {
+      const doc = parse(
+        JSON.stringify({
+          html: "<h2>Title</h2><p>Text with <b>bold</b> and <i>italic</i>.</p><ul><li>one</li></ul>",
+          tasks: [],
+        })
+      );
+      const types = typesIn(doc);
+      expect(types).toContain("heading");
+      expect(types).toContain("bulletList");
+      const marks = JSON.stringify(doc);
+      expect(marks).toContain("bold");
+      expect(marks).toContain("italic");
+    });
+
+    it("turns the detached task array into a task list, preserving checked state", () => {
+      const doc = parse(
+        JSON.stringify({
+          html: "<p>body</p>",
+          tasks: [
+            { id: "a", text: "done thing", done: true },
+            { id: "b", text: "open thing", done: false },
+          ],
+        })
+      );
+      expect(typesIn(doc)).toContain("taskList");
+      const json = JSON.stringify(doc);
+      expect(json).toContain("done thing");
+      expect(json).toContain("open thing");
+      // exactly one of the two items is checked
+      expect((json.match(/"checked":true/g) || []).length).toBe(1);
+    });
+
+    it("does not let task text smuggle in markup", () => {
+      const doc = parse(
+        JSON.stringify({ html: "", tasks: [{ id: "a", text: "<script>alert(1)</script>", done: false }] })
+      );
+      expect(typesIn(doc)).not.toContain("script");
+      expect(docToText(doc)).toContain("<script>");
+    });
+
+    it("accepts a bare HTML string, which the very first version stored", () => {
+      expect(typesIn(parse("<p>plain</p>"))).toContain("paragraph");
+    });
+
+    it("falls back to plain text rather than throwing on unparseable input", () => {
+      expect(() => parse("{ not json at all")).not.toThrow();
+    });
+  });
+});
+
+describe("serializeNoteContent", () => {
+  it("round-trips through parse", () => {
+    const doc = { type: "doc", content: [{ type: "paragraph", content: [{ type: "text", text: "x" }] }] };
+    expect(parse(serializeNoteContent(doc))).toEqual(doc);
+  });
+
+  it("tags the stored format so future versions can tell them apart", () => {
+    expect(JSON.parse(serializeNoteContent({ type: "doc" })).v).toBe(2);
+  });
+});
+
+describe("extractNoteLinks", () => {
+  const docWith = (...ids: string[]) => ({
+    type: "doc",
+    content: ids.map((id) => ({
+      type: "paragraph",
+      content: [{ type: "noteLink", attrs: { noteId: id, label: id } }],
+    })),
+  });
+
+  it("finds every linked id", () => {
+    expect(extractNoteLinks(docWith("a", "b")).sort()).toEqual(["a", "b"]);
+  });
+
+  it("deduplicates repeated links", () => {
+    expect(extractNoteLinks(docWith("a", "a", "a"))).toEqual(["a"]);
+  });
+
+  it("drops a link to the note itself", () => {
+    expect(extractNoteLinks(docWith("self", "other"), "self")).toEqual(["other"]);
+  });
+
+  it("finds links nested inside tables", () => {
+    const doc = {
+      type: "doc",
+      content: [
+        {
+          type: "table",
+          content: [
+            {
+              type: "tableRow",
+              content: [
+                {
+                  type: "tableCell",
+                  content: [
+                    {
+                      type: "paragraph",
+                      content: [{ type: "noteLink", attrs: { noteId: "deep", label: "d" } }],
+                    },
+                  ],
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    };
+    expect(extractNoteLinks(doc)).toEqual(["deep"]);
+  });
+
+  it("returns nothing for a document without links", () => {
+    expect(extractNoteLinks({ type: "doc", content: [{ type: "paragraph" }] })).toEqual([]);
+  });
+});
+
+describe("docToText", () => {
+  it("joins text across nested nodes", () => {
+    const doc = {
+      type: "doc",
+      content: [
+        { type: "paragraph", content: [{ type: "text", text: "first" }] },
+        {
+          type: "bulletList",
+          content: [
+            {
+              type: "listItem",
+              content: [{ type: "paragraph", content: [{ type: "text", text: "second" }] }],
+            },
+          ],
+        },
+      ],
+    };
+    expect(docToText(doc)).toBe("first second");
+  });
+
+  it("includes note link labels, so linked notes are searchable by name", () => {
+    const doc = {
+      type: "doc",
+      content: [{ type: "paragraph", content: [{ type: "noteLink", attrs: { label: "Recipes" } }] }],
+    };
+    expect(docToText(doc)).toContain("Recipes");
+  });
+
+  it("respects the length limit", () => {
+    const doc = {
+      type: "doc",
+      content: [{ type: "paragraph", content: [{ type: "text", text: "x".repeat(500) }] }],
+    };
+    expect(docToText(doc, 50).length).toBeLessThanOrEqual(50);
+  });
+});

frontend/src/editor/content.ts

@@ -0,0 +1,140 @@
+/**
+ * Note content format and migration.
+ *
+ * v1 (contentEditable era): JSON.stringify({ html, tasks }) — unstructured HTML
+ *   from document.execCommand plus a separate checkbox list. Tables could not
+ *   be represented reliably and links had no identity.
+ * v2 (current): JSON.stringify({ v: 2, doc }) where `doc` is a TipTap/ProseMirror
+ *   document. Structured, so tables, task lists and note links are real nodes.
+ *
+ * v1 notes are converted on read and rewritten as v2 the next time they are
+ * saved. Nothing is migrated in bulk, so an old client reading a note it has
+ * not touched still sees its own format.
+ */
+
+import { generateJSON } from "@tiptap/html";
+import type { Extensions } from "@tiptap/core";
+
+/** A TipTap/ProseMirror node. Deliberately loose: the schema is the authority. */
+export interface DocNode {
+  type?: string;
+  text?: string;
+  attrs?: Record<string, any>;
+  content?: DocNode[];
+}
+
+export const CONTENT_VERSION = 2;
+
+export const emptyDoc = (): DocNode => ({ type: "doc", content: [{ type: "paragraph" }] });
+
+const escapeHtml = (s: unknown): string =>
+  String(s ?? "")
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;");
+
+/** Renders a v1 `tasks` array as the HTML TipTap's TaskList parses. */
+function tasksToHtml(tasks: unknown): string {
+  if (!Array.isArray(tasks) || tasks.length === 0) return "";
+  const items = tasks
+    .map(
+      (t: { done?: boolean; text?: string }) =>
+        `<li data-type="taskItem" data-checked="${t.done ? "true" : "false"}"><p>${escapeHtml(t.text)}</p></li>`
+    )
+    .join("");
+  return `<ul data-type="taskList">${items}</ul>`;
+}
+
+/**
+ * Turns whatever is stored in `note.content` into a TipTap document.
+ * Never throws: a note that cannot be parsed opens empty rather than blocking
+ * the editor, and the original string is left untouched until the user edits.
+ */
+export function parseNoteContent(raw: unknown, extensions: Extensions): DocNode {
+  if (!raw) return emptyDoc();
+
+  let parsed: any = null;
+  if (typeof raw === "string") {
+    try {
+      parsed = JSON.parse(raw);
+    } catch {
+      parsed = null;
+    }
+  } else if (typeof raw === "object") {
+    parsed = raw;
+  }
+
+  // v2 — already a TipTap document.
+  if (parsed && parsed.v === CONTENT_VERSION && parsed.doc) return parsed.doc;
+
+  // v1 — HTML plus a detached task list, or a bare HTML string.
+  const html =
+    typeof parsed?.html === "string"
+      ? parsed.html
+      : typeof parsed === "string"
+        ? parsed
+        : typeof raw === "string"
+          ? raw
+          : "";
+  const combined = html + tasksToHtml(parsed?.tasks);
+  if (!combined.trim()) return emptyDoc();
+
+  try {
+    return generateJSON(combined, extensions);
+  } catch (err) {
+    console.error("[content] could not migrate v1 note, opening as plain text:", err);
+    return {
+      type: "doc",
+      content: [{ type: "paragraph", content: [{ type: "text", text: stripHtml(combined) }] }],
+    };
+  }
+}
+
+export function serializeNoteContent(doc: DocNode): string {
+  return JSON.stringify({ v: CONTENT_VERSION, doc });
+}
+
+function stripHtml(html: string): string {
+  const el = document.createElement("div");
+  el.innerHTML = html;
+  return el.textContent || "";
+}
+
+/** Depth-first walk over every node in a TipTap document. */
+function walk(node: DocNode | undefined | null, visit: (n: DocNode) => void): void {
+  if (!node) return;
+  visit(node);
+  if (Array.isArray(node.content)) for (const child of node.content) walk(child, visit);
+}
+
+/**
+ * Ids of every note this document links to.
+ *
+ * The server stores content encrypted and cannot read it, so the client is what
+ * tells it which links exist. Deduplicated and self-links dropped.
+ */
+export function extractNoteLinks(doc: DocNode, selfId?: string): string[] {
+  const ids = new Set<string>();
+  walk(doc, (n) => {
+    if (n.type === "noteLink" && n.attrs?.noteId && n.attrs.noteId !== selfId) ids.add(n.attrs.noteId);
+  });
+  return [...ids];
+}
+
+/** Plain text of a document — used for list previews and local search. */
+export function docToText(doc: unknown, limit = 400): string {
+  const parts: string[] = [];
+  let len = 0;
+  walk(doc as DocNode, (n) => {
+    if (len >= limit) return;
+    if (n.type === "text" && n.text) {
+      parts.push(n.text);
+      len += n.text.length;
+    } else if (n.type === "noteLink" && n.attrs?.label) {
+      parts.push(n.attrs.label);
+      len += n.attrs.label.length;
+    }
+  });
+  return parts.join(" ").replace(/\s+/g, " ").trim().slice(0, limit);
+}

frontend/src/editor/editor.css

@@ -0,0 +1,262 @@
+/* Editor content styling.
+ *
+ * The rest of the app styles inline, but ProseMirror renders its own DOM, so
+ * these nodes can only be reached from a stylesheet. Colours come from custom
+ * properties the editor container sets per theme. */
+
+.note-editor {
+  --ne-text: #1f2328;
+  --ne-muted: #656d76;
+  --ne-faint: #afb8c1;
+  --ne-border: #d0d7de;
+  --ne-accent: #0969da;
+  --ne-surface: #ffffff;
+  --ne-subtle: #f6f8fa;
+}
+.note-editor[data-theme="dark"] {
+  --ne-text: #e6edf3;
+  --ne-muted: #8b949e;
+  --ne-faint: #484f58;
+  --ne-border: #30363d;
+  --ne-accent: #388bfd;
+  --ne-surface: #0d1117;
+  --ne-subtle: #161b22;
+}
+
+.note-editor .ProseMirror {
+  outline: none;
+  color: var(--ne-text);
+  font-family: "Newsreader", Georgia, serif;
+  font-size: 15px;
+  line-height: 1.7;
+  padding: 20px 24px;
+  min-height: 100%;
+  word-break: break-word;
+}
+.note-editor .ProseMirror > * + * {
+  margin-top: 0.6em;
+}
+.note-editor .ProseMirror p {
+  margin: 0;
+}
+.note-editor .ProseMirror h1 {
+  font-size: 1.7em;
+  font-weight: 700;
+  line-height: 1.3;
+  margin-top: 0.8em;
+}
+.note-editor .ProseMirror h2 {
+  font-size: 1.4em;
+  font-weight: 700;
+  line-height: 1.3;
+  margin-top: 0.7em;
+}
+.note-editor .ProseMirror h3 {
+  font-size: 1.15em;
+  font-weight: 700;
+  line-height: 1.4;
+  margin-top: 0.6em;
+}
+.note-editor .ProseMirror ul,
+.note-editor .ProseMirror ol {
+  padding-left: 1.4em;
+}
+.note-editor .ProseMirror li p {
+  margin: 0;
+}
+.note-editor .ProseMirror blockquote {
+  border-left: 3px solid var(--ne-border);
+  padding-left: 12px;
+  color: var(--ne-muted);
+}
+.note-editor .ProseMirror code {
+  background: var(--ne-subtle);
+  border: 1px solid var(--ne-border);
+  border-radius: 4px;
+  padding: 1px 5px;
+  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
+  font-size: 0.88em;
+}
+.note-editor .ProseMirror pre {
+  background: var(--ne-subtle);
+  border: 1px solid var(--ne-border);
+  border-radius: 10px;
+  padding: 12px 14px;
+  overflow-x: auto;
+}
+.note-editor .ProseMirror pre code {
+  background: none;
+  border: none;
+  padding: 0;
+}
+.note-editor .ProseMirror hr {
+  border: none;
+  border-top: 1px solid var(--ne-border);
+  margin: 1.2em 0;
+}
+.note-editor .ProseMirror img {
+  max-width: 100%;
+  height: auto;
+  border-radius: 8px;
+  display: block;
+}
+.note-editor .ProseMirror img.note-image {
+  background: var(--ne-subtle);
+  min-height: 24px;
+}
+/* An attachment whose bytes could not be fetched — visible, not a blank gap */
+.note-editor .ProseMirror img[data-missing="true"] {
+  border: 1px dashed var(--ne-border);
+  padding: 12px;
+  min-width: 120px;
+}
+.note-editor .ProseMirror a {
+  color: var(--ne-accent);
+}
+
+/* Placeholder on the first empty line */
+.note-editor .ProseMirror p.is-editor-empty:first-child::before {
+  content: attr(data-placeholder);
+  color: var(--ne-faint);
+  float: left;
+  height: 0;
+  pointer-events: none;
+}
+
+/* ── Tables ── */
+.note-editor .ProseMirror table {
+  border-collapse: collapse;
+  table-layout: fixed;
+  width: 100%;
+  margin: 0.8em 0;
+  overflow: hidden;
+}
+.note-editor .ProseMirror td,
+.note-editor .ProseMirror th {
+  border: 1px solid var(--ne-border);
+  padding: 7px 10px;
+  vertical-align: top;
+  position: relative;
+  min-width: 1em;
+}
+.note-editor .ProseMirror th {
+  background: var(--ne-subtle);
+  font-weight: 600;
+  text-align: left;
+}
+.note-editor .ProseMirror .selectedCell::after {
+  content: "";
+  position: absolute;
+  inset: 0;
+  background: color-mix(in srgb, var(--ne-accent) 18%, transparent);
+  pointer-events: none;
+}
+/* Drag handle between columns */
+.note-editor .ProseMirror .column-resize-handle {
+  position: absolute;
+  right: -2px;
+  top: 0;
+  bottom: -2px;
+  width: 4px;
+  background: var(--ne-accent);
+  pointer-events: none;
+}
+.note-editor .ProseMirror.resize-cursor {
+  cursor: col-resize;
+}
+
+/* ── Task lists ── */
+.note-editor .ProseMirror ul[data-type="taskList"] {
+  list-style: none;
+  padding-left: 0;
+}
+.note-editor .ProseMirror ul[data-type="taskList"] li {
+  display: flex;
+  align-items: flex-start;
+  gap: 8px;
+}
+.note-editor .ProseMirror ul[data-type="taskList"] li > label {
+  flex: 0 0 auto;
+  margin-top: 0.35em;
+  user-select: none;
+}
+.note-editor .ProseMirror ul[data-type="taskList"] li > div {
+  flex: 1 1 auto;
+}
+.note-editor .ProseMirror ul[data-type="taskList"] input[type="checkbox"] {
+  accent-color: var(--ne-accent);
+  width: 15px;
+  height: 15px;
+  cursor: pointer;
+}
+.note-editor .ProseMirror ul[data-type="taskList"] li[data-checked="true"] > div {
+  color: var(--ne-muted);
+  text-decoration: line-through;
+}
+
+/* ── Note links ── */
+.note-editor .ProseMirror a.note-link,
+.note-link {
+  display: inline-flex;
+  align-items: baseline;
+  gap: 3px;
+  padding: 1px 6px;
+  border-radius: 6px;
+  background: color-mix(in srgb, var(--ne-accent) 14%, transparent);
+  color: var(--ne-accent);
+  text-decoration: none;
+  font-family: "DM Sans", system-ui, sans-serif;
+  font-size: 0.9em;
+  white-space: nowrap;
+  cursor: pointer;
+}
+.note-editor .ProseMirror a.note-link:hover {
+  background: color-mix(in srgb, var(--ne-accent) 26%, transparent);
+}
+/* A link whose target is gone — still readable, visibly broken */
+.note-editor .ProseMirror a.note-link[data-missing="true"] {
+  background: color-mix(in srgb, #cf222e 14%, transparent);
+  color: #cf222e;
+  text-decoration: line-through;
+}
+
+/* ── @-mention popup ── */
+.note-link-popup {
+  position: fixed;
+  z-index: 3000;
+  max-height: 240px;
+  overflow-y: auto;
+  padding: 5px;
+  border-radius: 12px;
+  border: 1px solid var(--popup-border, #d0d7de);
+  background: var(--popup-bg, #ffffff);
+  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.22);
+  font-family: "DM Sans", system-ui, sans-serif;
+}
+.note-link-option {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 7px 10px;
+  border: none;
+  border-radius: 8px;
+  background: transparent;
+  color: var(--popup-text, #1f2328);
+  font-size: 13px;
+  text-align: left;
+  cursor: pointer;
+}
+.note-link-option.is-selected {
+  background: var(--popup-hover, #eaeef2);
+}
+.note-link-option .note-link-label {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+.note-link-empty {
+  padding: 9px 11px;
+  font-size: 12px;
+  color: var(--popup-muted, #656d76);
+}

frontend/src/editor/extensions.js

@@ -0,0 +1,49 @@
+/** The one place that decides which nodes and marks a note may contain. */
+
+import StarterKit from "@tiptap/starter-kit";
+import Underline from "@tiptap/extension-underline";
+import Link from "@tiptap/extension-link";
+import Placeholder from "@tiptap/extension-placeholder";
+import TaskList from "@tiptap/extension-task-list";
+import TaskItem from "@tiptap/extension-task-item";
+import Table from "@tiptap/extension-table";
+import TableRow from "@tiptap/extension-table-row";
+import TableHeader from "@tiptap/extension-table-header";
+import TableCell from "@tiptap/extension-table-cell";
+
+import { NoteLink } from "./noteLink.js";
+import { AttachmentImage } from "./attachmentImage.js";
+
+export function buildExtensions({ search = () => [], placeholder = "Start writing..." } = {}) {
+  return [
+    StarterKit.configure({
+      heading: { levels: [1, 2, 3] },
+      // History is on by default; the drawing layer keeps its own undo stack.
+      codeBlock: { HTMLAttributes: { class: "note-code-block" } },
+    }),
+    Underline,
+    Link.configure({
+      openOnClick: false, // the app decides what a click does
+      autolink: true,
+      protocols: ["http", "https", "mailto"],
+      HTMLAttributes: { rel: "noopener noreferrer nofollow", target: "_blank" },
+    }),
+    // allowBase64 stays on so notes written before attachments still render.
+    AttachmentImage.configure({ inline: false, allowBase64: true }),
+    Placeholder.configure({ placeholder }),
+    TaskList,
+    TaskItem.configure({ nested: true }),
+    Table.configure({ resizable: true, lastColumnResizable: false, allowTableNodeSelection: true }),
+    TableRow,
+    TableHeader,
+    TableCell,
+    NoteLink.configure({ search }),
+  ];
+}
+
+/**
+ * A static extension list for parsing stored HTML outside of a live editor
+ * (`generateJSON`). It must accept everything `buildExtensions` produces, or
+ * migrating an old note would silently drop nodes.
+ */
+export const parsingExtensions = buildExtensions();

frontend/src/editor/noteLink.js

@@ -0,0 +1,221 @@
+/**
+ * Note links — type `@` to reference another note or notebook.
+ *
+ * A link is an atomic inline node carrying the target's id, so it survives
+ * renames: the label is refreshed from the current title on render, and the id
+ * is what the backlink index is built from.
+ */
+
+import { Node, mergeAttributes } from "@tiptap/core";
+import Suggestion from "@tiptap/suggestion";
+import { PluginKey } from "@tiptap/pm/state";
+
+export const NoteLinkPluginKey = new PluginKey("noteLinkSuggestion");
+
+export const NoteLink = Node.create({
+  name: "noteLink",
+  group: "inline",
+  inline: true,
+  atom: true,
+  selectable: true,
+  draggable: false,
+
+  addOptions() {
+    return {
+      // (query) => [{ id, label, kind: 'note' | 'notebook' }]
+      search: () => [],
+      HTMLAttributes: {},
+    };
+  },
+
+  addAttributes() {
+    return {
+      noteId: {
+        default: null,
+        parseHTML: (el) => el.getAttribute("data-note-link"),
+        renderHTML: (a) => ({ "data-note-link": a.noteId }),
+      },
+      label: {
+        default: "",
+        parseHTML: (el) => el.getAttribute("data-label") || el.textContent,
+        renderHTML: (a) => ({ "data-label": a.label }),
+      },
+      kind: {
+        default: "note",
+        parseHTML: (el) => el.getAttribute("data-kind") || "note",
+        renderHTML: (a) => ({ "data-kind": a.kind }),
+      },
+      // Set when the target no longer exists, so a dead link reads as broken
+      // instead of silently going nowhere.
+      missing: {
+        default: false,
+        parseHTML: (el) => el.getAttribute("data-missing") === "true",
+        renderHTML: (a) => (a.missing ? { "data-missing": "true" } : {}),
+      },
+    };
+  },
+
+  parseHTML() {
+    return [{ tag: "a[data-note-link]" }, { tag: "span[data-note-link]" }];
+  },
+
+  renderHTML({ node, HTMLAttributes }) {
+    return [
+      "a",
+      mergeAttributes(this.options.HTMLAttributes, HTMLAttributes, {
+        class: "note-link",
+        // Real href would navigate away; the app intercepts the click instead.
+        href: "#",
+        title: node.attrs.label,
+      }),
+      `${node.attrs.kind === "notebook" ? "📓" : "📝"} ${node.attrs.label}`,
+    ];
+  },
+
+  renderText({ node }) {
+    return `@${node.attrs.label}`;
+  },
+
+  addProseMirrorPlugins() {
+    return [
+      Suggestion({
+        editor: this.editor,
+        char: "@",
+        pluginKey: NoteLinkPluginKey,
+        allowSpaces: true,
+        startOfLine: false,
+        items: ({ query }) => this.options.search(query),
+        command: ({ editor, range, props }) => {
+          editor
+            .chain()
+            .focus()
+            .insertContentAt(range, [
+              {
+                type: "noteLink",
+                attrs: { noteId: props.id, label: props.label, kind: props.kind || "note" },
+              },
+              { type: "text", text: " " },
+            ])
+            .run();
+        },
+        render: renderSuggestionList,
+      }),
+    ];
+  },
+});
+
+/**
+ * A small dropdown driven by the suggestion plugin.
+ *
+ * Deliberately plain DOM rather than a positioning library — it is one list in
+ * one place, and pulling in tippy/popper for it is not worth the bundle.
+ */
+function renderSuggestionList() {
+  let el = null;
+  let items = [];
+  let selected = 0;
+  let command = null;
+
+  const paint = () => {
+    if (!el) return;
+    if (items.length === 0) {
+      el.innerHTML = '<div class="note-link-empty">No matching note</div>';
+      return;
+    }
+    el.innerHTML = items
+      .map(
+        (
+          it,
+          i
+        ) => `<button type="button" class="note-link-option${i === selected ? " is-selected" : ""}" data-index="${i}">
+          <span class="note-link-kind">${it.kind === "notebook" ? "📓" : "📝"}</span>
+          <span class="note-link-label"></span>
+        </button>`
+      )
+      .join("");
+    // Titles are user text — set them as text, never as markup.
+    el.querySelectorAll(".note-link-option").forEach((btn, i) => {
+      btn.querySelector(".note-link-label").textContent = items[i].label;
+      btn.addEventListener("mousedown", (e) => {
+        e.preventDefault();
+        pick(i);
+      });
+    });
+  };
+
+  const pick = (i) => {
+    const item = items[i];
+    if (item && command) command({ id: item.id, label: item.label, kind: item.kind });
+  };
+
+  const place = (rect) => {
+    if (!el || !rect) return;
+    const r = rect();
+    if (!r) return;
+    const width = 260;
+    const left = Math.min(Math.max(8, r.left), window.innerWidth - width - 8);
+    // Flip above the caret when there is no room below.
+    const below = window.innerHeight - r.bottom;
+    el.style.width = `${width}px`;
+    el.style.left = `${left}px`;
+    if (below < 220) {
+      el.style.top = "auto";
+      el.style.bottom = `${window.innerHeight - r.top + 6}px`;
+    } else {
+      el.style.bottom = "auto";
+      el.style.top = `${r.bottom + 6}px`;
+    }
+  };
+
+  return {
+    onStart: (props) => {
+      items = props.items || [];
+      selected = 0;
+      command = props.command;
+      el = document.createElement("div");
+      el.className = "note-link-popup";
+      document.body.appendChild(el);
+      paint();
+      place(props.clientRect);
+    },
+    onUpdate: (props) => {
+      items = props.items || [];
+      selected = Math.min(selected, Math.max(0, items.length - 1));
+      command = props.command;
+      paint();
+      place(props.clientRect);
+    },
+    onKeyDown: (props) => {
+      const key = props.event.key;
+      if (key === "Escape") {
+        props.event.preventDefault();
+        el?.remove();
+        el = null;
+        return true;
+      }
+      if (items.length === 0) return false;
+      if (key === "ArrowDown") {
+        selected = (selected + 1) % items.length;
+        paint();
+        return true;
+      }
+      if (key === "ArrowUp") {
+        selected = (selected - 1 + items.length) % items.length;
+        paint();
+        return true;
+      }
+      if (key === "Enter" || key === "Tab") {
+        props.event.preventDefault();
+        pick(selected);
+        return true;
+      }
+      return false;
+    },
+    onExit: () => {
+      el?.remove();
+      el = null;
+      items = [];
+      command = null;
+    },
+  };
+}

frontend/src/editor/useNoteEditor.jsx

@@ -0,0 +1,167 @@
+import { useEffect, useMemo, useRef, useCallback } from "react";
+import { useEditor, EditorContent } from "@tiptap/react";
+
+import { buildExtensions } from "./extensions.js";
+import { parseNoteContent, serializeNoteContent, extractNoteLinks } from "./content";
+import { uploadImage, ACCEPTED_TYPES } from "./attachments.js";
+import "./editor.css";
+
+/* Marks transactions this module dispatches itself, so they are not mistaken
+ * for the user editing the note. */
+const LABEL_REFRESH = "noteLinkLabelRefresh";
+
+/**
+ * Uploads images from a paste or drop and inserts them as attachments.
+ *
+ * Returns true only when images were actually taken over, so pasting text or a
+ * screenshot-free clipboard still behaves normally.
+ */
+function insertDroppedImages(view, transfer, at, onErrorRef) {
+  const files = [...(transfer?.files || [])].filter((f) => ACCEPTED_TYPES.includes(f.type));
+  if (files.length === 0) return false;
+
+  (async () => {
+    for (const file of files) {
+      try {
+        const id = await uploadImage(file);
+        const node = view.state.schema.nodes.image.create({ attachmentId: id, alt: file.name || null });
+        const pos = at ?? view.state.selection.from;
+        view.dispatch(view.state.tr.insert(Math.min(pos, view.state.doc.content.size), node));
+      } catch (err) {
+        console.error("[attachment] upload failed:", err);
+        onErrorRef?.current?.(err.message || "Could not attach that image");
+      }
+    }
+  })();
+
+  return true; // handled — do not also paste the raw file
+}
+
+/**
+ * Builds the note body editor.
+ *
+ * The instance is returned rather than kept inside a component because the
+ * toolbar lives elsewhere in the tree and needs the same editor to drive it.
+ */
+export function useNoteEditor({ noteId, content, editable = true, onChange, searchLinkTargets, onError }) {
+  // Held in refs so a changing callback identity never rebuilds the editor,
+  // which would drop the cursor and the undo history mid-typing.
+  const searchRef = useRef(searchLinkTargets);
+  searchRef.current = searchLinkTargets;
+  const onChangeRef = useRef(onChange);
+  onChangeRef.current = onChange;
+  const onErrorRef = useRef(onError);
+  onErrorRef.current = onError;
+
+  const extensions = useMemo(
+    () => buildExtensions({ search: (query) => (searchRef.current ? searchRef.current(query) : []) }),
+    []
+  );
+
+  const editor = useEditor(
+    {
+      extensions,
+      content: parseNoteContent(content, extensions),
+      editable,
+      editorProps: {
+        attributes: { spellcheck: "true" },
+        handlePaste: (view, event) => insertDroppedImages(view, event.clipboardData, null, onErrorRef),
+        handleDrop: (view, event) => {
+          const at = view.posAtCoords({ left: event.clientX, top: event.clientY })?.pos ?? null;
+          return insertDroppedImages(view, event.dataTransfer, at, onErrorRef);
+        },
+      },
+      onUpdate: ({ editor: ed, transaction }) => {
+        // Refreshing a link label is not a user edit and must not mark the note dirty.
+        if (transaction?.getMeta(LABEL_REFRESH)) return;
+        const doc = ed.getJSON();
+        onChangeRef.current?.({
+          content: serializeNoteContent(doc),
+          links: extractNoteLinks(doc, noteId),
+        });
+      },
+      // Rebuilt per note so each one starts with its own document and history.
+    },
+    [noteId]
+  );
+
+  useEffect(() => {
+    if (editor && editor.isEditable !== editable) editor.setEditable(editable);
+  }, [editor, editable]);
+
+  /* Adopt content that arrived from another device. Skipped while the editor
+   * has focus, so a sync push can never yank the document out from under the
+   * cursor, and skipped when nothing actually differs. */
+  useEffect(() => {
+    if (!editor || editor.isDestroyed || editor.isFocused) return;
+    const incoming = parseNoteContent(content, extensions);
+    if (JSON.stringify(incoming) === JSON.stringify(editor.getJSON())) return;
+    editor.commands.setContent(incoming, false);
+  }, [editor, content, extensions]);
+
+  return editor;
+}
+
+/** The editable page itself. */
+export function EditorSurface({ editor, dark, minHeight, onOpenNote, resolveLinkLabel }) {
+  /* Note links carry the label they were created with, so renaming a note would
+   * leave every reference to it showing the old title.
+   *
+   * This has to go through a transaction. Writing the new label straight into
+   * `editor.view.dom` looks simpler and works on screen, but ProseMirror's
+   * mutation observer then re-reads the document from that DOM and drops the
+   * node — the link survived on screen and vanished on the next reload. */
+  useEffect(() => {
+    if (!editor || editor.isDestroyed || !resolveLinkLabel) return;
+    const edits = [];
+    editor.state.doc.descendants((node, pos) => {
+      if (node.type.name !== "noteLink") return;
+      const label = resolveLinkLabel(node.attrs.noteId);
+      const missing = label === null;
+      const nextLabel = missing ? node.attrs.label : label;
+      if (nextLabel !== node.attrs.label || missing !== !!node.attrs.missing) {
+        edits.push([pos, { ...node.attrs, label: nextLabel, missing }]);
+      }
+    });
+    if (edits.length === 0) return;
+    const tr = editor.state.tr;
+    for (const [pos, attrs] of edits) tr.setNodeMarkup(pos, undefined, attrs);
+    tr.setMeta(LABEL_REFRESH, true);
+    tr.setMeta("addToHistory", false); // undo should not step through renames
+    editor.view.dispatch(tr);
+  }, [editor, resolveLinkLabel]);
+
+  const handleClick = useCallback(
+    (e) => {
+      const noteLink = e.target.closest("a.note-link");
+      if (noteLink) {
+        e.preventDefault();
+        const id = noteLink.getAttribute("data-note-link");
+        if (id && !noteLink.hasAttribute("data-missing")) {
+          onOpenNote?.(id, noteLink.getAttribute("data-kind") || "note");
+        }
+        return;
+      }
+      const external = e.target.closest("a[href]");
+      if (external) {
+        const url = external.getAttribute("href");
+        if (url && /^(https?|mailto):/i.test(url)) {
+          e.preventDefault();
+          window.open(url, "_blank", "noopener");
+        }
+      }
+    },
+    [onOpenNote]
+  );
+
+  return (
+    <div
+      className="note-editor"
+      data-theme={dark ? "dark" : "light"}
+      onClick={handleClick}
+      style={{ minHeight }}
+    >
+      <EditorContent editor={editor} />
+    </div>
+  );
+}

frontend/src/features/drawing/DrawingLayer.jsx

@@ -0,0 +1,18 @@
+import { useEffect, useRef } from "react";
+import { sizeCanvas, paintStrokeDoc, strokeDocOf } from "./strokes.js";
+
+export function DrawingLayer({ strokes, width, height, zIndex }) {
+  const ref = useRef(null);
+  useEffect(() => {
+    const c = ref.current;
+    if (!c) return;
+    const { bw, bh } = sizeCanvas(c, width, height);
+    paintStrokeDoc(c.getContext("2d"), strokeDocOf(strokes), bw, bh);
+  }, [strokes, width, height]);
+  return (
+    <canvas
+      ref={ref}
+      style={{ position: "absolute", left: 0, top: 0, width: "100%", height, pointerEvents: "none", zIndex }}
+    />
+  );
+}

frontend/src/features/drawing/strokes.js

@@ -0,0 +1,105 @@
+import * as sync from "../../syncEngine";
+
+/* ═══════ DRAWING MODEL ═══════
+ * A drawing is a list of vector strokes in one canonical page space (CANON_W ×
+ * CANON_H), never a bitmap. Every screen scales that same page to whatever room
+ * it has, so a note looks identical on a phone and on a desktop — and stays
+ * sharp at any pixel density, because we rasterize at render time.
+ */
+export const CANON_W = 1200,
+  CANON_H = 1600;
+export const PREVIEW_DRAWING_W = 260; // history preview thumbnail
+export const STROKES_VERSION = 1;
+
+// Widths are canonical units, so a "Medium" pen covers the same fraction of the
+// page everywhere. At the 760px desktop page width, M lands at roughly 3.5 CSS px.
+export const PEN_SIZES = [
+  { label: "XS", w: 2 },
+  { label: "S", w: 3.5 },
+  { label: "M", w: 5.5 },
+  { label: "L", w: 9 },
+  { label: "XL", w: 14 },
+  { label: "2XL", w: 22 },
+  { label: "3XL", w: 34 },
+];
+export const DEFAULT_PEN_SIZE = 2; // index into PEN_SIZES → "M"
+export const HIGHLIGHTER_FACTOR = 5;
+export const ERASER_FACTOR = 4;
+export const HIGHLIGHTER_ALPHA = "55";
+// Minimum canonical distance between recorded points — keeps payloads small
+// without visibly changing the curve.
+export const MIN_POINT_DIST = 2.5;
+
+// `t` tags a save so the editor can recognise its own drawing coming back from
+// the server and ignore reads that were already in flight when it saved.
+let saveSeq = 0;
+export const newSaveToken = () => `${sync.DEVICE_ID}:${Date.now()}:${++saveSeq}`;
+export const strokeDocOf = (strokes, t) => ({
+  v: STROKES_VERSION,
+  w: CANON_W,
+  h: CANON_H,
+  strokes,
+  ...(t ? { t } : {}),
+});
+export const docStrokes = (doc) => (Array.isArray(doc?.strokes) ? doc.strokes : []);
+export const sameStrokeDoc = (a, b) =>
+  a === b ||
+  (docStrokes(a).length === docStrokes(b).length && docStrokes(a).every((s, i) => s === docStrokes(b)[i]));
+
+export function paintStroke(ctx, s) {
+  const p = s?.p;
+  if (!p || p.length < 2) return;
+  const eraser = s.t === "eraser";
+  ctx.globalCompositeOperation = eraser ? "destination-out" : "source-over";
+  const color = s.t === "highlighter" ? s.c + HIGHLIGHTER_ALPHA : s.c;
+  ctx.strokeStyle = color;
+  ctx.lineWidth = s.s;
+
+  if (p.length === 2) {
+    // a tap, not a drag — draw the nib itself
+    ctx.beginPath();
+    ctx.arc(p[0], p[1], Math.max(s.s / 2, 0.4), 0, Math.PI * 2);
+    ctx.fillStyle = color;
+    ctx.fill();
+    ctx.globalCompositeOperation = "source-over";
+    return;
+  }
+
+  // One path per stroke: a translucent highlighter stays evenly translucent
+  // instead of darkening at every joint.
+  ctx.beginPath();
+  ctx.moveTo(p[0], p[1]);
+  for (let i = 2; i < p.length - 2; i += 2) {
+    ctx.quadraticCurveTo(p[i], p[i + 1], (p[i] + p[i + 2]) / 2, (p[i + 1] + p[i + 3]) / 2);
+  }
+  ctx.lineTo(p[p.length - 2], p[p.length - 1]);
+  ctx.stroke();
+  ctx.globalCompositeOperation = "source-over";
+}
+
+// Replays a whole drawing into a context of targetW × targetH device pixels.
+export function paintStrokeDoc(ctx, doc, targetW, targetH) {
+  const w = doc?.w || CANON_W,
+    h = doc?.h || CANON_H;
+  ctx.setTransform(1, 0, 0, 1, 0, 0);
+  ctx.clearRect(0, 0, targetW, targetH);
+  ctx.scale(targetW / w, targetH / h);
+  ctx.lineCap = "round";
+  ctx.lineJoin = "round";
+  for (const s of docStrokes(doc)) paintStroke(ctx, s);
+  ctx.setTransform(1, 0, 0, 1, 0, 0);
+}
+
+export const backingScale = () => Math.min(window.devicePixelRatio || 1, 3);
+export function sizeCanvas(c, cssW, cssH) {
+  const dpr = backingScale();
+  const bw = Math.max(1, Math.round(cssW * dpr)),
+    bh = Math.max(1, Math.round(cssH * dpr));
+  if (c.width !== bw || c.height !== bh) {
+    c.width = bw;
+    c.height = bh;
+  }
+  return { bw, bh };
+}
+
+/* Read-only drawing layer — used wherever a saved drawing is shown but not edited. */

frontend/src/features/notebooks/Dashboard.jsx

@@ -0,0 +1,234 @@
+import { COVERS } from "../../ui/constants.jsx";
+import { I } from "../../ui/icons.jsx";
+import { NotebookCover } from "../../ui/NotebookCover.jsx";
+import { fmtDate } from "../../ui/format";
+import { FONT_SERIF, FONT_UI } from "../../ui/theme";
+
+const RECENT_COUNT = 6;
+
+/** Landing view: every notebook as a cover, plus the notes touched most recently. */
+export function Dashboard({
+  T,
+  isMobile,
+  notebooks,
+  activeNotes,
+  activeFolder,
+  onToggleSidebar,
+  onOpenNotebook,
+  onOpenNote,
+  onNewNotebook,
+  onNotebookContextMenu,
+  dnd,
+}) {
+  return (
+    <div
+      style={{
+        flex: 1,
+        display: "flex",
+        flexDirection: "column",
+        background: T.dashBg,
+        fontFamily: FONT_UI,
+        overflow: "auto",
+      }}
+    >
+      <div
+        style={{
+          padding: isMobile ? "20px 20px 16px" : "28px 36px 20px",
+          display: "flex",
+          alignItems: "center",
+          justifyContent: "space-between",
+        }}
+      >
+        <div style={{ display: "flex", alignItems: "center", gap: 10 }}>
+          <button
+            onClick={onToggleSidebar}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+              width: 36,
+              height: 36,
+              borderRadius: 10,
+              border: "none",
+              background: "transparent",
+              cursor: "pointer",
+              color: T.muted,
+            }}
+          >
+            {I.menu}
+          </button>
+          <h1
+            style={{
+              margin: 0,
+              fontSize: isMobile ? 20 : 24,
+              fontWeight: 700,
+              color: T.text,
+              fontFamily: FONT_SERIF,
+            }}
+          >
+            My Notebooks
+          </h1>
+        </div>
+      </div>
+
+      <div
+        style={{
+          padding: isMobile ? "0 16px 24px" : "0 36px 32px",
+          display: "grid",
+          gridTemplateColumns: isMobile
+            ? "repeat(auto-fill,minmax(140px,1fr))"
+            : "repeat(auto-fill,minmax(180px,1fr))",
+          gap: isMobile ? "20px 16px" : "32px 28px",
+          justifyItems: "center",
+        }}
+      >
+        {notebooks.map((nb) => (
+          <NotebookCover
+            key={nb.id}
+            notebook={nb}
+            noteCount={activeNotes.filter((n) => n.folderId === nb.id).length}
+            onClick={() => onOpenNotebook(nb.id)}
+            onContextMenu={(e) => onNotebookContextMenu(e, nb)}
+            isActive={activeFolder === nb.id}
+            isDragOver={dnd.overId === nb.id}
+            draggable={!isMobile}
+            onDragStart={(e) => dnd.onDragStart(e, nb.id)}
+            onDragEnd={dnd.onDragEnd}
+            onDragOver={(e) => dnd.onDragOver(e, nb.id)}
+            onDrop={(e) => dnd.onDrop(e, nb.id)}
+          />
+        ))}
+        <button
+          onClick={onNewNotebook}
+          style={{
+            display: "flex",
+            flexDirection: "column",
+            alignItems: "center",
+            gap: 10,
+            background: "none",
+            border: "none",
+            cursor: "pointer",
+          }}
+        >
+          <div
+            style={{
+              width: isMobile ? 130 : 156,
+              height: isMobile ? 175 : 210,
+              borderRadius: 12,
+              border: `2px dashed ${T.border}`,
+              display: "flex",
+              flexDirection: "column",
+              alignItems: "center",
+              justifyContent: "center",
+              gap: 8,
+              color: T.faint,
+            }}
+          >
+            <div
+              style={{
+                width: 40,
+                height: 40,
+                borderRadius: "50%",
+                background: T.accentSoft,
+                display: "flex",
+                alignItems: "center",
+                justifyContent: "center",
+                color: T.accent,
+              }}
+            >
+              {I.plus}
+            </div>
+            <span style={{ fontSize: 12, fontWeight: 500 }}>Add Notebook</span>
+          </div>
+        </button>
+      </div>
+
+      <div style={{ padding: isMobile ? "0 16px 24px" : "0 36px 36px" }}>
+        <h2
+          style={{
+            fontSize: 16,
+            fontWeight: 600,
+            color: T.text,
+            marginBottom: 14,
+            fontFamily: FONT_SERIF,
+          }}
+        >
+          Recent Notes
+        </h2>
+        <div
+          style={{
+            display: "grid",
+            gridTemplateColumns: isMobile ? "1fr" : "repeat(auto-fill,minmax(260px,1fr))",
+            gap: 12,
+          }}
+        >
+          {activeNotes.slice(0, RECENT_COUNT).map((note) => {
+            const nb = notebooks.find((b) => b.id === note.folderId);
+            return (
+              <button
+                key={note.id}
+                onClick={() => onOpenNote(note)}
+                style={{
+                  display: "flex",
+                  flexDirection: "column",
+                  padding: "14px 16px",
+                  borderRadius: 12,
+                  border: `1px solid ${T.border}`,
+                  background: T.card,
+                  cursor: "pointer",
+                  textAlign: "left",
+                }}
+              >
+                <div
+                  style={{ display: "flex", alignItems: "center", gap: 8, marginBottom: 6, width: "100%" }}
+                >
+                  {nb && (
+                    <div
+                      style={{
+                        width: 14,
+                        height: 10,
+                        borderRadius: 2,
+                        background: COVERS[nb.cover % COVERS.length].bg,
+                        flexShrink: 0,
+                      }}
+                    />
+                  )}
+                  <span
+                    style={{
+                      fontSize: 13,
+                      fontWeight: 600,
+                      color: T.text,
+                      flex: 1,
+                      overflow: "hidden",
+                      textOverflow: "ellipsis",
+                      whiteSpace: "nowrap",
+                    }}
+                  >
+                    {note.title}
+                  </span>
+                  {note.starred && <span style={{ color: "#f0b429", fontSize: 11 }}>⭐</span>}
+                </div>
+                <div style={{ display: "flex", alignItems: "center", gap: 6, marginTop: 6 }}>
+                  <span style={{ fontSize: 11, color: T.faint }}>{fmtDate(note.updatedAt)}</span>
+                  {nb && (
+                    <span
+                      style={{
+                        fontSize: 10,
+                        color: T.faint,
+                        background: T.accentSoft,
+                        padding: "1px 6px",
+                        borderRadius: 6,
+                      }}
+                    >
+                      {nb.name}
+                    </span>
+                  )}
+                </div>
+              </button>
+            );
+          })}
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/features/notes/EditorPane.jsx

@@ -0,0 +1,221 @@
+import { I } from "../../ui/icons.jsx";
+import { BackButton } from "../../ui/BackButton.jsx";
+import { FONT_SERIF, FONT_UI } from "../../ui/theme";
+import { NoteEditor } from "./NoteEditor.jsx";
+
+const toolbarButton = (T, color) => ({
+  display: "flex",
+  alignItems: "center",
+  justifyContent: "center",
+  width: 30,
+  height: 30,
+  borderRadius: 8,
+  border: "none",
+  background: "transparent",
+  cursor: "pointer",
+  color,
+});
+
+/** Shown on desktop when nothing is selected; on a phone the list fills the screen instead. */
+function EmptyState({ T, isTrashView, onCreateNote }) {
+  return (
+    <div
+      style={{
+        flex: 1,
+        display: "flex",
+        flexDirection: "column",
+        alignItems: "center",
+        justifyContent: "center",
+        background: T.bg,
+        color: T.faint,
+        fontFamily: FONT_UI,
+        gap: 14,
+      }}
+    >
+      <div
+        style={{
+          width: 72,
+          height: 72,
+          borderRadius: 20,
+          background: T.accentSoft,
+          display: "flex",
+          alignItems: "center",
+          justifyContent: "center",
+          fontSize: 32,
+        }}
+      >
+        ✏️
+      </div>
+      <div style={{ fontSize: 15, fontWeight: 500, color: T.muted }}>Select a note to edit</div>
+      {!isTrashView && (
+        <button
+          onClick={onCreateNote}
+          style={{
+            display: "flex",
+            alignItems: "center",
+            gap: 8,
+            padding: "10px 22px",
+            borderRadius: 12,
+            border: "none",
+            background: T.accent,
+            color: "#fff",
+            cursor: "pointer",
+            fontSize: 13,
+            fontWeight: 600,
+            marginTop: 6,
+          }}
+        >
+          {I.plus} New Note
+        </button>
+      )}
+    </div>
+  );
+}
+
+/** A trashed note can be read and restored, but not edited. */
+function TrashedNote({ T, isMobile, note, onBack, onRestore, onPermanentDelete }) {
+  return (
+    <div style={{ flex: 1, display: "flex", flexDirection: "column", background: T.bg, fontFamily: FONT_UI }}>
+      <div
+        style={{
+          display: "flex",
+          alignItems: "center",
+          gap: 8,
+          padding: "12px 16px",
+          borderBottom: `1px solid ${T.borderLight}`,
+        }}
+      >
+        {isMobile && <BackButton T={T} onClick={onBack} />}
+        <span
+          style={{
+            fontSize: 17,
+            fontWeight: 600,
+            color: T.text,
+            fontFamily: FONT_SERIF,
+            flex: 1,
+            overflow: "hidden",
+            textOverflow: "ellipsis",
+            whiteSpace: "nowrap",
+          }}
+        >
+          {note.title}
+        </span>
+        <button
+          onClick={onRestore}
+          style={{
+            padding: "6px 14px",
+            borderRadius: 8,
+            border: "none",
+            background: T.accent,
+            color: "#fff",
+            cursor: "pointer",
+            fontSize: 12,
+            fontWeight: 600,
+          }}
+        >
+          Restore
+        </button>
+        <button onClick={onPermanentDelete} style={toolbarButton(T, T.danger)}>
+          {I.trash}
+        </button>
+      </div>
+      <div style={{ flex: 1, padding: "20px 24px", color: T.muted, fontStyle: "italic", fontSize: 14 }}>
+        Trashed notes are read-only. Restore to edit.
+      </div>
+    </div>
+  );
+}
+
+/**
+ * The right-hand pane: title bar plus the rich-text editor.
+ *
+ * `restoreEpoch` is part of the editor's key so that restoring an old version
+ * remounts it on the restored body instead of trying to merge into the live
+ * document.
+ */
+export function EditorPane({
+  T,
+  dark,
+  isMobile,
+  note,
+  isTrashView,
+  restoreEpoch,
+  backlinks,
+  linkProps,
+  onBack,
+  onUpdate,
+  onToggleStar,
+  onTrash,
+  onRestore,
+  onPermanentDelete,
+  onOpenHistory,
+  onCreateNote,
+}) {
+  if (!note)
+    return isMobile ? null : <EmptyState T={T} isTrashView={isTrashView} onCreateNote={onCreateNote} />;
+
+  if (isTrashView)
+    return (
+      <TrashedNote
+        T={T}
+        isMobile={isMobile}
+        note={note}
+        onBack={onBack}
+        onRestore={onRestore}
+        onPermanentDelete={onPermanentDelete}
+      />
+    );
+
+  return (
+    <div style={{ flex: 1, display: "flex", flexDirection: "column", background: T.bg, fontFamily: FONT_UI }}>
+      <div
+        style={{
+          display: "flex",
+          alignItems: "center",
+          gap: 8,
+          padding: "8px 16px",
+          borderBottom: `1px solid ${T.borderLight}`,
+        }}
+      >
+        {isMobile && <BackButton T={T} onClick={onBack} />}
+        <input
+          type="text"
+          value={note.title}
+          onChange={(e) => onUpdate({ title: e.target.value })}
+          style={{
+            flex: 1,
+            border: "none",
+            background: "transparent",
+            outline: "none",
+            fontSize: isMobile ? 15 : 17,
+            fontWeight: 600,
+            color: T.text,
+            fontFamily: FONT_SERIF,
+            minWidth: 0,
+          }}
+        />
+        <button onClick={onOpenHistory} title="Version history" style={toolbarButton(T, T.faint)}>
+          {I.history}
+        </button>
+        <button onClick={onToggleStar} style={toolbarButton(T, note.starred ? "#f0b429" : T.faint)}>
+          {note.starred ? I.starFill : I.star}
+        </button>
+        <button onClick={onTrash} style={toolbarButton(T, T.danger)}>
+          {I.trash}
+        </button>
+      </div>
+      <div style={{ flex: 1, overflow: "hidden" }}>
+        <NoteEditor
+          key={`${note.id}:${restoreEpoch}`}
+          note={note}
+          onUpdate={onUpdate}
+          dark={dark}
+          onOpenNote={linkProps.openLinkTarget}
+          searchLinkTargets={linkProps.searchLinkTargets}
+          resolveLinkLabel={linkProps.resolveLinkLabel}
+          backlinks={backlinks}
+        />
+      </div>
+    </div>
+  );
+}

frontend/src/features/notes/HistoryModal.jsx

@@ -0,0 +1,297 @@
+import { useEffect, useMemo, useState } from "react";
+import * as sync from "../../syncEngine";
+import { VersionPreview } from "../../editor/VersionPreview.jsx";
+import { I } from "../../ui/icons.jsx";
+
+/* ═══════ VERSION HISTORY ═══════ */
+/* Past states of a note, newest first. The server keeps a snapshot of what a
+ * note looked like before each editing session, so an overwrite that is only
+ * noticed later can still be undone. */
+export function HistoryModal({ noteId, noteTitle, dark, onClose, onRestored, renderDrawing }) {
+  const [versions, setVersions] = useState(null);
+  const [selectedId, setSelectedId] = useState(null);
+  const [detail, setDetail] = useState(null);
+  const [loading, setLoading] = useState(false);
+  const [restoring, setRestoring] = useState(false);
+  const [err, setErr] = useState("");
+
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      accent: dark ? "#388bfd" : "#0969da",
+      danger: dark ? "#f85149" : "#cf222e",
+      surface: dark ? "#0d1117" : "#f6f8fa",
+    }),
+    [dark]
+  );
+
+  useEffect(() => {
+    let cancelled = false;
+    sync
+      .getNoteVersions(noteId)
+      .then((v) => {
+        if (cancelled) return;
+        setVersions(v);
+        if (v.length) setSelectedId(v[0].id);
+      })
+      .catch(() => {
+        if (!cancelled) setVersions([]);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [noteId]);
+
+  useEffect(() => {
+    if (!selectedId) return;
+    let cancelled = false;
+    setLoading(true);
+    setErr("");
+    sync
+      .getNoteVersion(noteId, selectedId)
+      .then((d) => {
+        if (!cancelled) setDetail(d);
+      })
+      .catch((e) => {
+        if (!cancelled) setErr(e.message || "Could not load this version");
+      })
+      .finally(() => {
+        if (!cancelled) setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [noteId, selectedId]);
+
+  const restore = async () => {
+    if (!selectedId) return;
+    setRestoring(true);
+    setErr("");
+    try {
+      const r = await sync.restoreNoteVersion(noteId, selectedId);
+      onRestored?.(r.content);
+      onClose();
+    } catch (e) {
+      setErr(e.message || "Restore failed");
+    }
+    setRestoring(false);
+  };
+
+  const when = (t) => {
+    const d = new Date(String(t).replace(" ", "T") + "Z");
+    return d.toLocaleString(undefined, {
+      month: "short",
+      day: "numeric",
+      hour: "2-digit",
+      minute: "2-digit",
+    });
+  };
+  const REASONS = {
+    "large-deletion": "large deletion",
+    "before-restore": "before restore",
+    "drawing-cleared": "drawing cleared",
+    drawing: "drawing",
+    edit: "edit",
+  };
+
+  return (
+    <div
+      style={{
+        position: "fixed",
+        inset: 0,
+        background: "rgba(0,0,0,0.55)",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        zIndex: 2000,
+        backdropFilter: "blur(6px)",
+      }}
+      onClick={onClose}
+    >
+      <div
+        onClick={(e) => e.stopPropagation()}
+        style={{
+          background: T.bg,
+          borderRadius: 20,
+          width: 940,
+          maxWidth: "94vw",
+          height: 620,
+          maxHeight: "88vh",
+          border: `1px solid ${T.border}`,
+          boxShadow: "0 24px 48px rgba(0,0,0,0.3)",
+          display: "flex",
+          flexDirection: "column",
+          overflow: "hidden",
+        }}
+      >
+        <div
+          style={{
+            display: "flex",
+            alignItems: "center",
+            justifyContent: "space-between",
+            padding: "16px 20px",
+            borderBottom: `1px solid ${T.border}`,
+          }}
+        >
+          <div>
+            <h3
+              style={{
+                margin: 0,
+                fontSize: 16,
+                fontWeight: 600,
+                color: T.text,
+                fontFamily: "'Newsreader',Georgia,serif",
+              }}
+            >
+              Version history
+            </h3>
+            <div style={{ fontSize: 12, color: T.muted, marginTop: 2 }}>{noteTitle || "Untitled"}</div>
+          </div>
+          <button
+            onClick={onClose}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+              width: 28,
+              height: 28,
+              borderRadius: 8,
+              border: "none",
+              background: "transparent",
+              cursor: "pointer",
+              color: T.muted,
+            }}
+          >
+            {I.x}
+          </button>
+        </div>
+
+        <div style={{ flex: 1, display: "flex", minHeight: 0 }}>
+          {/* Version list */}
+          <div
+            style={{
+              width: 260,
+              flexShrink: 0,
+              borderRight: `1px solid ${T.border}`,
+              overflowY: "auto",
+              padding: 8,
+              background: T.surface,
+            }}
+          >
+            {versions === null && <div style={{ padding: 14, fontSize: 12, color: T.muted }}>Loading…</div>}
+            {versions?.length === 0 && (
+              <div style={{ padding: 14, fontSize: 12, color: T.muted, lineHeight: 1.6 }}>
+                No earlier versions yet. One is kept whenever you come back to a note after a break, and
+                always before a large deletion.
+              </div>
+            )}
+            {versions?.map((v) => (
+              <button
+                key={v.id}
+                onClick={() => setSelectedId(v.id)}
+                style={{
+                  display: "block",
+                  width: "100%",
+                  textAlign: "left",
+                  padding: "9px 11px",
+                  marginBottom: 3,
+                  borderRadius: 9,
+                  border: "none",
+                  cursor: "pointer",
+                  background: selectedId === v.id ? T.accent + "22" : "transparent",
+                }}
+              >
+                <div
+                  style={{ fontSize: 12.5, fontWeight: 600, color: selectedId === v.id ? T.accent : T.text }}
+                >
+                  {when(v.created_at)}
+                </div>
+                <div style={{ fontSize: 11, color: T.muted, marginTop: 2 }}>
+                  {REASONS[v.reason] || v.reason}
+                  {v.has_drawing && " · drawing"}
+                </div>
+              </button>
+            ))}
+          </div>
+
+          {/* Preview */}
+          <div style={{ flex: 1, overflowY: "auto", minWidth: 0, position: "relative" }}>
+            {loading && <div style={{ padding: 20, fontSize: 12, color: T.muted }}>Loading version…</div>}
+            {!loading && detail && (
+              <>
+                {detail.drawingStrokes && renderDrawing && (
+                  <div
+                    style={{
+                      margin: "14px 18px 0",
+                      border: `1px solid ${T.border}`,
+                      borderRadius: 10,
+                      overflow: "hidden",
+                      position: "relative",
+                      background: dark ? "#0d1117" : "#fff",
+                    }}
+                  >
+                    {renderDrawing(detail.drawingStrokes)}
+                  </div>
+                )}
+                <VersionPreview content={detail.content} dark={dark} />
+              </>
+            )}
+            {!loading && !detail && !err && versions?.length > 0 && (
+              <div style={{ padding: 20, fontSize: 12, color: T.muted }}>Select a version.</div>
+            )}
+          </div>
+        </div>
+
+        <div
+          style={{
+            display: "flex",
+            alignItems: "center",
+            justifyContent: "space-between",
+            gap: 12,
+            padding: "12px 20px",
+            borderTop: `1px solid ${T.border}`,
+          }}
+        >
+          <div style={{ fontSize: 11.5, color: err ? T.danger : T.muted, flex: 1, minWidth: 0 }}>
+            {err || "Restoring keeps a snapshot of the current state first, so this is reversible."}
+          </div>
+          <button
+            onClick={onClose}
+            style={{
+              padding: "8px 18px",
+              borderRadius: 10,
+              border: `1px solid ${T.border}`,
+              background: "transparent",
+              color: T.text,
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Close
+          </button>
+          <button
+            onClick={restore}
+            disabled={!selectedId || restoring || loading}
+            style={{
+              padding: "8px 18px",
+              borderRadius: 10,
+              border: "none",
+              background: T.accent,
+              color: "#fff",
+              cursor: selectedId ? "pointer" : "default",
+              fontSize: 13,
+              fontWeight: 600,
+              opacity: !selectedId || restoring || loading ? 0.5 : 1,
+            }}
+          >
+            {restoring ? "Restoring…" : "Restore this version"}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/features/notes/NoteEditor.jsx

@@ -0,0 +1,691 @@
+import { useEffect, useMemo, useRef, useState } from "react";
+import { useNoteEditor, EditorSurface } from "../../editor/useNoteEditor.jsx";
+import { EditorToolbar } from "../../editor/EditorToolbar.jsx";
+import { DrawingLayer } from "../drawing/DrawingLayer.jsx";
+import {
+  CANON_W,
+  CANON_H,
+  PEN_SIZES,
+  DEFAULT_PEN_SIZE,
+  HIGHLIGHTER_FACTOR,
+  ERASER_FACTOR,
+  MIN_POINT_DIST,
+  newSaveToken,
+  strokeDocOf,
+  docStrokes,
+  paintStroke,
+  paintStrokeDoc,
+  sizeCanvas,
+} from "../drawing/strokes.js";
+import { COLORS } from "../../ui/constants.jsx";
+import { I } from "../../ui/icons.jsx";
+import { BacklinksPanel } from "../../ui/BacklinksPanel.jsx";
+
+/* ═══════ NOTE EDITOR ═══════ */
+export function NoteEditor({
+  note,
+  onUpdate,
+  dark,
+  onOpenNote,
+  searchLinkTargets,
+  resolveLinkLabel,
+  backlinks,
+}) {
+  const [mode, setMode] = useState("text");
+  const canvasRef = useRef(null);
+  const [tool, setTool] = useState("pen");
+  const [penColor, setPenColor] = useState(dark ? "#e6edf3" : "#1a1a2e");
+  const [penSizeIdx, setPenSizeIdx] = useState(DEFAULT_PEN_SIZE);
+  const [undoStack, setUndoStack] = useState([]);
+  const [redoStack, setRedoStack] = useState([]);
+  const [showColors, setShowColors] = useState(false);
+  const [showSizes, setShowSizes] = useState(false);
+  const [hideDrawing, setHideDrawing] = useState(false);
+  const [drawingBlend, setDrawingBlend] = useState({ mode: "normal", opacity: 1 });
+  const [isMobileViewport, setIsMobileViewport] = useState(window.innerWidth < 768);
+  const stageRef = useRef(null);
+  const saveTimerRef = useRef(null);
+  const dirtyRef = useRef(false);
+  const SAVE_DEBOUNCE_MS = 600;
+  const [stageSize, setStageSize] = useState({ w: CANON_W, h: CANON_H });
+
+  /* ── DRAWING STATE ──
+   * strokesRef is what the pointer handlers read and write synchronously;
+   * `strokes` mirrors it so React can repaint the read-only layer. */
+  const strokesRef = useRef([]);
+  const [strokes, setStrokes] = useState([]);
+  const liveRef = useRef(null); // stroke currently under the pointer
+  const drawingRef = useRef(false);
+  const committedRef = useRef(null); // offscreen canvas holding all finished strokes
+  const appliedDocRef = useRef(undefined);
+  const pendingTokenRef = useRef(null);
+  const hasStrokes = strokes.length > 0;
+  // Old notes may still carry a raster drawing. It stays visible underneath any
+  // new vector strokes so migrating a note never loses what was already drawn.
+  const legacyRaster = note.drawingData && !hideDrawing;
+
+  const commitStrokes = (next) => {
+    strokesRef.current = next;
+    setStrokes(next);
+  };
+
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#0d1117" : "#ffffff",
+      toolbar: dark ? "#161b22" : "#f6f8fa",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      active: dark ? "#388bfd" : "#0969da",
+      faint: dark ? "#484f58" : "#afb8c1",
+    }),
+    [dark]
+  );
+
+  /* The note body. Structured TipTap document — tables, task lists and note
+   * links are real nodes, not HTML that happened to survive execCommand. */
+  const [editorNotice, setEditorNotice] = useState("");
+  const textEditor = useNoteEditor({
+    noteId: note.id,
+    content: note.content,
+    editable: mode === "text",
+    searchLinkTargets,
+    onChange: ({ content, links }) => onUpdate({ content, links }),
+    onError: (msg) => {
+      setEditorNotice(msg);
+      setTimeout(() => setEditorNotice(""), 5000);
+    },
+  });
+
+  useEffect(() => {
+    setHideDrawing(false);
+    const isLegacyRaster =
+      typeof note.drawingData === "string" && /^data:image\/(jpeg|jpg|webp)/i.test(note.drawingData);
+    if (!note.drawingData) {
+      setDrawingBlend({ mode: "normal", opacity: 1 });
+      return;
+    }
+    let cancelled = false;
+    const img = new Image();
+    img.onload = () => {
+      if (cancelled) return;
+      try {
+        const c = document.createElement("canvas");
+        c.width = 32;
+        c.height = 32;
+        const cx = c.getContext("2d", { willReadFrequently: true });
+        if (!cx) throw new Error("ctx");
+        cx.drawImage(img, 0, 0, 32, 32);
+        const data = cx.getImageData(0, 0, 32, 32).data;
+        let solid = 0,
+          black = 0;
+        for (let i = 0; i < data.length; i += 4) {
+          const a = data[i + 3];
+          if (a < 245) continue;
+          solid++;
+          if (data[i] < 16 && data[i + 1] < 16 && data[i + 2] < 16) black++;
+        }
+        const blackRatio = solid ? black / solid : 0;
+        if (blackRatio > 0.9) setDrawingBlend({ mode: "screen", opacity: 0.62 });
+        else if (isLegacyRaster) setDrawingBlend({ mode: "screen", opacity: 0.42 });
+        else setDrawingBlend({ mode: "normal", opacity: 1 });
+      } catch {
+        setDrawingBlend(isLegacyRaster ? { mode: "screen", opacity: 0.42 } : { mode: "normal", opacity: 1 });
+      }
+    };
+    img.onerror = () => {
+      if (!cancelled) setHideDrawing(true);
+    };
+    img.src = note.drawingData;
+    return () => {
+      cancelled = true;
+    };
+  }, [note.id, note.drawingData]);
+
+  // Keep one fixed-aspect drawing stage regardless of device dimensions.
+  useEffect(() => {
+    const fitStage = () => {
+      const host = stageRef.current;
+      if (!host) return;
+      const W = Math.max(1, host.clientWidth);
+      const mobile = window.innerWidth < 768;
+      setIsMobileViewport(mobile);
+      const sidePad = mobile ? 10 : 28;
+      const desktopMax = 760;
+      const minW = mobile ? 220 : 320;
+      const maxAllowed = Math.max(220, W - sidePad * 2);
+      const targetW = mobile ? maxAllowed : Math.min(desktopMax, maxAllowed);
+      const w = Math.floor(Math.max(minW, targetW));
+      const h = Math.floor((w * CANON_H) / CANON_W);
+      setStageSize({ w, h });
+    };
+    fitStage();
+    if (typeof ResizeObserver !== "undefined") {
+      const ro = new ResizeObserver(fitStage);
+      if (stageRef.current) ro.observe(stageRef.current);
+      window.addEventListener("resize", fitStage);
+      return () => {
+        ro.disconnect();
+        window.removeEventListener("resize", fitStage);
+      };
+    }
+    window.addEventListener("resize", fitStage);
+    return () => window.removeEventListener("resize", fitStage);
+  }, []);
+
+  const saveDrawingNow = () => {
+    if (!dirtyRef.current) return;
+    const token = newSaveToken();
+    const doc = strokeDocOf(strokesRef.current, token);
+    appliedDocRef.current = doc; // ignore the echo coming straight back through props
+    pendingTokenRef.current = token; // ...and any server read still in flight
+    dirtyRef.current = false;
+    onUpdate({ drawingStrokes: doc });
+  };
+  const scheduleDrawingSave = () => {
+    if (saveTimerRef.current) clearTimeout(saveTimerRef.current);
+    saveTimerRef.current = setTimeout(() => {
+      saveTimerRef.current = null;
+      saveDrawingNow();
+    }, SAVE_DEBOUNCE_MS);
+  };
+
+  /* ── DRAWING: painting ── */
+  const renderFrame = () => {
+    const c = canvasRef.current;
+    if (!c) return;
+    const ctx = c.getContext("2d");
+    ctx.setTransform(1, 0, 0, 1, 0, 0);
+    ctx.clearRect(0, 0, c.width, c.height);
+    if (committedRef.current) ctx.drawImage(committedRef.current, 0, 0);
+    const live = liveRef.current;
+    if (live) {
+      ctx.save();
+      ctx.scale(c.width / CANON_W, c.height / CANON_H);
+      ctx.lineCap = "round";
+      ctx.lineJoin = "round";
+      paintStroke(ctx, live);
+      ctx.restore();
+    }
+  };
+  // Repaint the offscreen canvas from scratch, then show it. Cheap enough at
+  // stroke boundaries, and it keeps eraser strokes ordered correctly.
+  const repaintAll = () => {
+    const c = canvasRef.current;
+    if (!c) return;
+    const { bw, bh } = sizeCanvas(c, stageSize.w, stageSize.h);
+    let off = committedRef.current;
+    if (!off) {
+      off = document.createElement("canvas");
+      committedRef.current = off;
+    }
+    if (off.width !== bw || off.height !== bh) {
+      off.width = bw;
+      off.height = bh;
+    }
+    paintStrokeDoc(off.getContext("2d"), strokeDocOf(strokesRef.current), bw, bh);
+    renderFrame();
+  };
+
+  /* Adopt strokes arriving from props (note switch, or a sync push from another
+   * device) without throwing away strokes we have not saved yet. */
+  useEffect(() => {
+    const doc = note.drawingStrokes || null;
+    if (appliedDocRef.current === doc) return;
+    appliedDocRef.current = doc;
+    if (dirtyRef.current) return; // strokes in hand that are not saved yet
+    if (pendingTokenRef.current) {
+      // A save is on its way to the server. Until it comes back, any doc we get
+      // is a read that started before it — adopting it would drop fresh strokes.
+      if (doc?.t !== pendingTokenRef.current) return;
+      pendingTokenRef.current = null; // our own save echoed back; in sync again
+      return;
+    }
+    commitStrokes(docStrokes(doc));
+    setUndoStack([]);
+    setRedoStack([]);
+    repaintAll();
+  }, [note.id, note.drawingStrokes]);
+
+  useEffect(() => {
+    if (mode === "draw") repaintAll();
+  }, [mode, stageSize.w, stageSize.h]);
+
+  /* ── DRAWING: input ── */
+  const canonPos = (e) => {
+    const r = canvasRef.current.getBoundingClientRect();
+    const t = e.touches ? e.touches[0] : e;
+    return { x: (t.clientX - r.left) * (CANON_W / r.width), y: (t.clientY - r.top) * (CANON_H / r.height) };
+  };
+  const currentStrokeWidth = () => {
+    const base = PEN_SIZES[penSizeIdx].w;
+    if (tool === "highlighter") return base * HIGHLIGHTER_FACTOR;
+    if (tool === "eraser") return base * ERASER_FACTOR;
+    return base;
+  };
+  const r1 = (n) => Math.round(n * 10) / 10;
+
+  const startDraw = (e) => {
+    if (mode !== "draw") return;
+    e.preventDefault();
+    const p = canonPos(e);
+    liveRef.current = { t: tool, c: penColor, s: r1(currentStrokeWidth()), p: [r1(p.x), r1(p.y)] };
+    drawingRef.current = true;
+    renderFrame();
+  };
+  const doDraw = (e) => {
+    if (!drawingRef.current) return;
+    e.preventDefault();
+    const p = canonPos(e),
+      live = liveRef.current,
+      n = live.p.length;
+    const dx = p.x - live.p[n - 2],
+      dy = p.y - live.p[n - 1];
+    if (dx * dx + dy * dy < MIN_POINT_DIST * MIN_POINT_DIST) return;
+    live.p.push(r1(p.x), r1(p.y));
+    renderFrame();
+  };
+  const stopDraw = (e) => {
+    if (!drawingRef.current) return;
+    e?.preventDefault();
+    drawingRef.current = false;
+    const live = liveRef.current;
+    liveRef.current = null;
+    if (!live) {
+      renderFrame();
+      return;
+    }
+    pushUndo();
+    commitStrokes([...strokesRef.current, live]);
+    dirtyRef.current = true;
+    repaintAll();
+    scheduleDrawingSave();
+  };
+
+  /* ── DRAWING: history ── */
+  const pushUndo = () => {
+    setUndoStack((p) => [...p.slice(-30), strokesRef.current]);
+    setRedoStack([]);
+  };
+  const applyHistory = (next) => {
+    commitStrokes(next);
+    dirtyRef.current = true;
+    repaintAll();
+    scheduleDrawingSave();
+  };
+  const undo = () => {
+    if (!undoStack.length) return;
+    const prev = undoStack[undoStack.length - 1];
+    setUndoStack((p) => p.slice(0, -1));
+    setRedoStack((p) => [...p, strokesRef.current]);
+    applyHistory(prev);
+  };
+  const redo = () => {
+    if (!redoStack.length) return;
+    const next = redoStack[redoStack.length - 1];
+    setRedoStack((p) => p.slice(0, -1));
+    setUndoStack((p) => [...p, strokesRef.current]);
+    applyHistory(next);
+  };
+  const clearCanvas = () => {
+    pushUndo();
+    applyHistory([]);
+  };
+
+  /* Save drawing on mode switch and debounced stroke-end updates. */
+  const switchMode = (m) => {
+    if (mode === "draw" && m !== "draw" && dirtyRef.current) {
+      if (saveTimerRef.current) {
+        clearTimeout(saveTimerRef.current);
+        saveTimerRef.current = null;
+      }
+      saveDrawingNow();
+    }
+    setMode(m);
+    setShowColors(false);
+    setShowSizes(false);
+  };
+
+  useEffect(
+    () => () => {
+      if (saveTimerRef.current) clearTimeout(saveTimerRef.current);
+      saveDrawingNow();
+    },
+    []
+  );
+
+  /* ── TEXT ──
+   * Image paste, drag-to-resize and the execCommand toolbar used to live
+   * here. TipTap owns the document now, so formatting goes through editor
+   * commands rather than a deprecated browser API. */
+
+  /* ── RENDER ── */
+  const tb = (a) => ({
+    display: "flex",
+    alignItems: "center",
+    justifyContent: "center",
+    width: 30,
+    height: 30,
+    borderRadius: 6,
+    border: "none",
+    cursor: "pointer",
+    background: a ? T.active + "22" : "transparent",
+    color: a ? T.active : T.text,
+    transition: "all .12s",
+    flexShrink: 0,
+  });
+  const mb = (m, ic, lb) => (
+    <button
+      onClick={() => switchMode(m)}
+      style={{
+        display: "flex",
+        alignItems: "center",
+        gap: 6,
+        padding: "6px 12px",
+        borderRadius: 8,
+        fontSize: 12,
+        fontWeight: 600,
+        border: `1.5px solid ${mode === m ? T.active : T.border}`,
+        background: mode === m ? T.active + "15" : "transparent",
+        color: mode === m ? T.active : T.muted,
+        cursor: "pointer",
+        flexShrink: 0,
+      }}
+    >
+      {ic}
+      <span>{lb}</span>
+    </button>
+  );
+
+  return (
+    <div
+      style={{
+        display: "flex",
+        flexDirection: "column",
+        height: "100%",
+        background: isMobileViewport
+          ? T.bg
+          : dark
+            ? "linear-gradient(180deg,#0f141b 0%,#0d1117 60%)"
+            : "linear-gradient(180deg,#f8fafd 0%,#eef3f8 70%)",
+      }}
+    >
+      {/* Main toolbar */}
+      <div
+        style={{
+          display: "flex",
+          alignItems: "center",
+          gap: 6,
+          padding: "7px 14px",
+          borderBottom: `1px solid ${T.border}`,
+          background: T.toolbar,
+          flexWrap: "wrap",
+          minHeight: 46,
+        }}
+      >
+        {mb("text", I.text, "Write")}
+        {mb("draw", I.draw, "Draw")}
+        <div style={{ width: 1, height: 22, background: T.border, margin: "0 2px", flexShrink: 0 }} />
+        {mode === "text" ? (
+          <EditorToolbar
+            editor={textEditor}
+            T={{ ...T, danger: "#e5534b" }}
+            icons={I}
+            compact={isMobileViewport}
+          />
+        ) : (
+          <>
+            <button style={tb(tool === "pen")} onClick={() => setTool("pen")}>
+              {I.pen}
+            </button>
+            <button style={tb(tool === "highlighter")} onClick={() => setTool("highlighter")}>
+              {I.highlight}
+            </button>
+            <button style={tb(tool === "eraser")} onClick={() => setTool("eraser")}>
+              {I.eraser}
+            </button>
+            <div style={{ width: 1, height: 22, background: T.border, margin: "0 2px" }} />
+            <button style={tb()} onClick={undo}>
+              {I.undo}
+            </button>
+            <button style={tb()} onClick={redo}>
+              {I.redo}
+            </button>
+            <div style={{ width: 1, height: 22, background: T.border, margin: "0 2px" }} />
+            <div style={{ position: "relative" }}>
+              <button
+                style={tb(showColors)}
+                onClick={() => {
+                  setShowColors(!showColors);
+                  setShowSizes(false);
+                }}
+              >
+                <div
+                  style={{
+                    width: 18,
+                    height: 18,
+                    borderRadius: "50%",
+                    background: penColor,
+                    border: `2px solid ${T.border}`,
+                  }}
+                />
+              </button>
+              {showColors && (
+                <div
+                  style={{
+                    position: "absolute",
+                    top: 36,
+                    left: 0,
+                    background: T.toolbar,
+                    border: `1px solid ${T.border}`,
+                    borderRadius: 12,
+                    padding: 8,
+                    display: "grid",
+                    gridTemplateColumns: "repeat(5,1fr)",
+                    gap: 4,
+                    zIndex: 100,
+                    boxShadow: "0 8px 20px rgba(0,0,0,.2)",
+                  }}
+                >
+                  {COLORS.map((c) => (
+                    <button
+                      key={c}
+                      onClick={() => {
+                        setPenColor(c);
+                        setShowColors(false);
+                      }}
+                      style={{
+                        width: 26,
+                        height: 26,
+                        borderRadius: "50%",
+                        background: c,
+                        border: penColor === c ? `3px solid ${T.active}` : `1px solid ${T.border}`,
+                        cursor: "pointer",
+                      }}
+                    />
+                  ))}
+                </div>
+              )}
+            </div>
+            <div style={{ position: "relative" }}>
+              <button
+                style={tb(showSizes)}
+                onClick={() => {
+                  setShowSizes(!showSizes);
+                  setShowColors(false);
+                }}
+              >
+                <div
+                  style={{
+                    width: Math.min(4 + penSizeIdx * 2, 16),
+                    height: Math.min(4 + penSizeIdx * 2, 16),
+                    borderRadius: "50%",
+                    background: T.text,
+                  }}
+                />
+              </button>
+              {showSizes && (
+                <div
+                  style={{
+                    position: "absolute",
+                    top: 36,
+                    left: 0,
+                    background: T.toolbar,
+                    border: `1px solid ${T.border}`,
+                    borderRadius: 12,
+                    padding: 8,
+                    display: "flex",
+                    flexDirection: "column",
+                    gap: 4,
+                    zIndex: 100,
+                    boxShadow: "0 8px 20px rgba(0,0,0,.2)",
+                  }}
+                >
+                  {PEN_SIZES.map((s, i) => (
+                    <button
+                      key={s.label}
+                      onClick={() => {
+                        setPenSizeIdx(i);
+                        setShowSizes(false);
+                      }}
+                      style={{
+                        display: "flex",
+                        alignItems: "center",
+                        gap: 8,
+                        padding: "3px 8px",
+                        borderRadius: 6,
+                        border: "none",
+                        cursor: "pointer",
+                        background: penSizeIdx === i ? T.active + "22" : "transparent",
+                      }}
+                    >
+                      <div
+                        style={{
+                          width: Math.min(4 + i * 3, 22),
+                          height: Math.min(4 + i * 3, 22),
+                          borderRadius: "50%",
+                          background: T.text,
+                          flexShrink: 0,
+                        }}
+                      />
+                      <span style={{ fontSize: 11, color: T.muted }}>{s.label}</span>
+                    </button>
+                  ))}
+                </div>
+              )}
+            </div>
+            <div style={{ flex: 1 }} />
+            <button style={{ ...tb(), color: "#e5534b" }} onClick={clearCanvas}>
+              {I.trash}
+            </button>
+          </>
+        )}
+      </div>
+
+      {editorNotice && (
+        <div
+          style={{
+            padding: "7px 14px",
+            background: "#e5534b18",
+            color: "#e5534b",
+            fontSize: 12,
+            borderBottom: `1px solid ${T.border}`,
+          }}
+        >
+          {editorNotice}
+        </div>
+      )}
+
+      {/* Content area */}
+      <div ref={stageRef} style={{ flex: 1, position: "relative", overflow: "hidden" }}>
+        <div
+          style={{
+            position: "absolute",
+            inset: 0,
+            overflowY: "auto",
+            WebkitOverflowScrolling: "touch",
+            zIndex: 1,
+            padding: isMobileViewport ? "10px 0 18px" : "18px 0 28px",
+          }}
+        >
+          <div
+            style={{
+              position: "relative",
+              width: stageSize.w,
+              minHeight: stageSize.h,
+              margin: isMobileViewport ? "0 auto" : "0 0 0 28px",
+              background: T.bg,
+              border: isMobileViewport ? "none" : `1px solid ${T.border}`,
+              borderRadius: isMobileViewport ? 0 : 14,
+              boxShadow: isMobileViewport ? "none" : "0 16px 36px rgba(0,0,0,0.14)",
+            }}
+          >
+            <div
+              style={{
+                minHeight: stageSize.h,
+                width: "100%",
+                pointerEvents: mode === "text" ? "auto" : "none",
+              }}
+            >
+              <EditorSurface
+                editor={textEditor}
+                dark={dark}
+                minHeight={stageSize.h}
+                onOpenNote={onOpenNote}
+                resolveLinkLabel={resolveLinkLabel}
+              />
+            </div>
+            {/* Legacy raster drawing from before vector strokes — kept underneath so nothing is lost */}
+            {legacyRaster && (
+              <img
+                src={note.drawingData}
+                alt=""
+                onError={() => setHideDrawing(true)}
+                style={{
+                  position: "absolute",
+                  left: 0,
+                  top: 0,
+                  width: "100%",
+                  height: stageSize.h,
+                  pointerEvents: "none",
+                  objectFit: "fill",
+                  zIndex: 2,
+                  opacity: drawingBlend.opacity,
+                  mixBlendMode: drawingBlend.mode,
+                }}
+              />
+            )}
+            {/* Saved drawing — re-rendered from vectors, so identical on every screen */}
+            {hasStrokes && mode !== "draw" && (
+              <DrawingLayer strokes={strokes} width={stageSize.w} height={stageSize.h} zIndex={2} />
+            )}
+            {mode === "draw" && (
+              <canvas
+                ref={canvasRef}
+                onMouseDown={startDraw}
+                onMouseMove={doDraw}
+                onMouseUp={stopDraw}
+                onMouseLeave={stopDraw}
+                onTouchStart={startDraw}
+                onTouchMove={doDraw}
+                onTouchEnd={stopDraw}
+                style={{
+                  position: "absolute",
+                  left: 0,
+                  top: 0,
+                  width: "100%",
+                  height: stageSize.h,
+                  touchAction: "none",
+                  cursor: "crosshair",
+                  background: "transparent",
+                  zIndex: 3,
+                }}
+              />
+            )}
+          </div>
+        </div>
+      </div>
+      {mode === "text" && <BacklinksPanel backlinks={backlinks} onOpenNote={onOpenNote} dark={dark} />}
+    </div>
+  );
+}

frontend/src/features/notes/NoteList.jsx

@@ -0,0 +1,217 @@
+import { I } from "../../ui/icons.jsx";
+import { fmtDate } from "../../ui/format";
+import { FONT_SERIF, FONT_UI } from "../../ui/theme";
+
+/** The middle column: every note in the selected folder, newest or best match first. */
+export function NoteList({
+  T,
+  isMobile,
+  title,
+  notes,
+  activeNote,
+  isTrashView,
+  trashedCount,
+  snippetFor,
+  onToggleSidebar,
+  onSelectNote,
+  onNoteContextMenu,
+  onCreateNote,
+  onEmptyTrash,
+}) {
+  return (
+    <div
+      style={{
+        width: isMobile ? "100%" : 300,
+        minWidth: isMobile ? 0 : 300,
+        flex: isMobile ? 1 : undefined,
+        borderRight: isMobile ? "none" : `1px solid ${T.border}`,
+        display: "flex",
+        flexDirection: "column",
+        background: T.bg,
+        fontFamily: FONT_UI,
+      }}
+    >
+      <div
+        style={{
+          padding: "14px 16px 10px",
+          display: "flex",
+          alignItems: "center",
+          justifyContent: "space-between",
+          borderBottom: `1px solid ${T.borderLight}`,
+        }}
+      >
+        <div style={{ display: "flex", alignItems: "center", gap: 8 }}>
+          <button
+            onClick={onToggleSidebar}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+              width: 30,
+              height: 30,
+              borderRadius: 8,
+              border: "none",
+              background: "transparent",
+              cursor: "pointer",
+              color: T.muted,
+            }}
+          >
+            {I.menu}
+          </button>
+          <h2 style={{ margin: 0, fontSize: 16, fontWeight: 600, color: T.text, fontFamily: FONT_SERIF }}>
+            {title}
+          </h2>
+        </div>
+        <div style={{ display: "flex", gap: 4 }}>
+          {!isTrashView && (
+            <button
+              onClick={onCreateNote}
+              title="New Note"
+              style={{
+                display: "flex",
+                alignItems: "center",
+                justifyContent: "center",
+                width: 32,
+                height: 32,
+                borderRadius: 10,
+                border: "none",
+                background: T.accent,
+                cursor: "pointer",
+                color: "#fff",
+                boxShadow: `0 2px 8px ${T.accent}44`,
+              }}
+            >
+              {I.plus}
+            </button>
+          )}
+          {isTrashView && trashedCount > 0 && (
+            <button
+              onClick={onEmptyTrash}
+              title="Empty Trash"
+              style={{
+                display: "flex",
+                alignItems: "center",
+                justifyContent: "center",
+                padding: "6px 12px",
+                borderRadius: 10,
+                border: "none",
+                background: T.danger,
+                cursor: "pointer",
+                color: "#fff",
+                fontSize: 12,
+                fontWeight: 600,
+              }}
+            >
+              Empty
+            </button>
+          )}
+        </div>
+      </div>
+
+      <div style={{ flex: 1, overflowY: "auto", padding: 6, WebkitOverflowScrolling: "touch" }}>
+        {notes.length === 0 ? (
+          <div
+            style={{
+              display: "flex",
+              flexDirection: "column",
+              alignItems: "center",
+              justifyContent: "center",
+              height: "100%",
+              color: T.faint,
+              gap: 10,
+              padding: 30,
+            }}
+          >
+            <div style={{ fontSize: 36 }}>{isTrashView ? "🗑️" : "📝"}</div>
+            <div style={{ fontSize: 13, textAlign: "center" }}>
+              {isTrashView ? "Trash is empty" : "No notes yet"}
+            </div>
+            {!isTrashView && (
+              <button
+                onClick={onCreateNote}
+                style={{
+                  display: "flex",
+                  alignItems: "center",
+                  gap: 6,
+                  padding: "10px 20px",
+                  borderRadius: 12,
+                  border: "none",
+                  background: T.accent,
+                  color: "#fff",
+                  cursor: "pointer",
+                  fontSize: 13,
+                  fontWeight: 600,
+                  marginTop: 8,
+                }}
+              >
+                {I.plus} New Note
+              </button>
+            )}
+          </div>
+        ) : (
+          notes.map((note) => {
+            const snippet = snippetFor(note.id);
+            return (
+              <button
+                key={note.id}
+                onClick={() => onSelectNote(note.id)}
+                onContextMenu={(e) => onNoteContextMenu(e, note)}
+                style={{
+                  display: "flex",
+                  flexDirection: "column",
+                  width: "100%",
+                  padding: "12px 14px",
+                  borderRadius: 10,
+                  border: `1px solid ${activeNote === note.id ? T.accent + "55" : "transparent"}`,
+                  background: activeNote === note.id ? T.accentSoft : "transparent",
+                  cursor: "pointer",
+                  marginBottom: 2,
+                  textAlign: "left",
+                }}
+              >
+                <div
+                  style={{ display: "flex", alignItems: "center", gap: 7, marginBottom: 3, width: "100%" }}
+                >
+                  <span style={{ fontSize: 13 }}>{note.trashed ? "🗑️" : "📝"}</span>
+                  <span
+                    style={{
+                      fontSize: 13,
+                      fontWeight: 600,
+                      color: T.text,
+                      flex: 1,
+                      overflow: "hidden",
+                      textOverflow: "ellipsis",
+                      whiteSpace: "nowrap",
+                    }}
+                  >
+                    {note.title}
+                  </span>
+                  {note.starred && !note.trashed && (
+                    <span style={{ color: "#f0b429", fontSize: 11 }}>⭐</span>
+                  )}
+                </div>
+                {snippet && (
+                  <div
+                    style={{
+                      fontSize: 11,
+                      color: T.textSec,
+                      lineHeight: 1.45,
+                      marginTop: 1,
+                      display: "-webkit-box",
+                      WebkitLineClamp: 2,
+                      WebkitBoxOrient: "vertical",
+                      overflow: "hidden",
+                    }}
+                  >
+                    {snippet}
+                  </div>
+                )}
+                <div style={{ fontSize: 10, color: T.faint, marginTop: 3 }}>{fmtDate(note.updatedAt)}</div>
+              </button>
+            );
+          })
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/hooks/useNavigationHistory.ts

@@ -0,0 +1,72 @@
+import { useEffect, useRef } from "react";
+
+import type { MobileView } from "./useResponsive";
+
+export interface NavState {
+  folder: string;
+  note: string | null;
+  view: MobileView;
+}
+
+const same = (a: NavState, b: NavState) => a.folder === b.folder && a.note === b.note && a.view === b.view;
+
+/**
+ * Maps the app's current location onto browser history, so the phone's back
+ * gesture steps back through notes and notebooks instead of leaving the app.
+ *
+ * `apply` is called when the user navigates back and should adopt the state it
+ * is handed.
+ */
+export function useNavigationHistory(
+  current: NavState,
+  isMobile: boolean,
+  apply: (state: NavState) => void
+): void {
+  const applyRef = useRef(apply);
+  applyRef.current = apply;
+  const currentRef = useRef(current);
+  currentRef.current = current;
+  const mobileRef = useRef(isMobile);
+  mobileRef.current = isMobile;
+
+  /** What the topmost history entry represents. */
+  const pushed = useRef<NavState>({ folder: "dashboard", note: null, view: "list" });
+
+  useEffect(() => {
+    if (same(pushed.current, current)) return;
+    pushed.current = { ...current };
+    try {
+      window.history.pushState(pushed.current, "");
+    } catch {
+      /* pushState is rate-limited in some browsers; losing an entry is not fatal */
+    }
+  }, [current.folder, current.note, current.view]);
+
+  useEffect(() => {
+    const onPop = (e: PopStateEvent) => {
+      const state = e.state as Partial<NavState> | null;
+      const cur = currentRef.current;
+      const view = mobileRef.current ? (state?.view ?? "list") : cur.view;
+
+      let next: NavState;
+      if (state) {
+        next = { folder: state.folder || "dashboard", note: state.note ?? null, view };
+      } else if (cur.note) {
+        // Stepping back past our own entries: close the note, then the notebook.
+        next = { folder: cur.folder, note: null, view: mobileRef.current ? "list" : cur.view };
+      } else if (cur.folder !== "dashboard") {
+        next = { folder: "dashboard", note: null, view: cur.view };
+      } else {
+        return;
+      }
+
+      // Record where history now stands *before* applying it. Without this the
+      // push effect sees a change it did not make and pushes a duplicate entry,
+      // which makes the back button bounce between two views forever.
+      pushed.current = next;
+      applyRef.current(next);
+    };
+    window.addEventListener("popstate", onPop);
+    return () => window.removeEventListener("popstate", onPop);
+  }, []);
+}

frontend/src/hooks/useNoteData.ts

@@ -0,0 +1,302 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+
+import * as sync from "../syncEngine";
+import * as searchIndex from "../search";
+import { sameStrokeDoc } from "../features/drawing/strokes.js";
+import type { Backlink, NoteContent, NoteMeta, Notebook, StrokeDoc, User } from "../types";
+
+/** How often the whole account is reconciled with the server. */
+const FULL_SYNC_MS = 30_000;
+/** How often the open note is re-read, so a second device's edits show up. */
+const ACTIVE_NOTE_POLL_MS = 6_000;
+/** After this long without a body arriving, show an empty editor rather than a spinner. */
+const CONTENT_TIMEOUT_MS = 5_000;
+
+const EMPTY_CONTENT: NoteContent = { content: "", drawingData: null, drawingStrokes: null };
+
+export interface NoteEdit {
+  title?: string;
+  content?: string;
+  /** Ids of notes and notebooks the body links to; stored server-side for backlinks. */
+  links?: string[];
+  drawingStrokes?: StrokeDoc | null;
+}
+
+export interface NoteData {
+  notes: NoteMeta[];
+  notebooks: Notebook[];
+  noteContents: Record<string, NoteContent>;
+  /** Notes linking to the currently open one. */
+  backlinks: Backlink[];
+
+  reload: () => Promise<void>;
+  reset: () => void;
+
+  createNote: (folderId: string) => Promise<NoteMeta>;
+  updateNote: (id: string, edit: NoteEdit) => void;
+  setNoteContent: (id: string, content: NoteContent) => void;
+  toggleStar: (id: string) => Promise<void>;
+  trashNote: (id: string) => Promise<void>;
+  restoreNote: (id: string) => Promise<void>;
+  permanentDeleteNote: (id: string) => Promise<void>;
+  emptyTrash: () => Promise<void>;
+  moveNote: (id: string, folderId: string) => Promise<void>;
+
+  createNotebook: (fields: { name: string; cover: number }) => Promise<Notebook>;
+  updateNotebook: (id: string, updates: Partial<Notebook>) => Promise<void>;
+  deleteNotebook: (id: string) => Promise<void>;
+  reorderNotebooks: (dragId: string, targetId: string) => void;
+}
+
+/**
+ * Owns everything the app knows about notes and notebooks: the local copy, the
+ * mutations that change it, and the background work that keeps it current.
+ *
+ * Every mutation writes locally first and hands the change to the sync engine,
+ * so the UI stays responsive and offline edits are never lost. Confirmation
+ * prompts are deliberately *not* here — destructive intent is a question for
+ * the interface, not the store.
+ */
+export function useNoteData(user: User | null, activeNote: string | null): NoteData {
+  const [notes, setNotes] = useState<NoteMeta[]>([]);
+  const [notebooks, setNotebooks] = useState<Notebook[]>([]);
+  const [noteContents, setNoteContents] = useState<Record<string, NoteContent>>({});
+  const [backlinks, setBacklinks] = useState<Backlink[]>([]);
+
+  const notesRef = useRef(notes);
+  notesRef.current = notes;
+  const notebooksRef = useRef(notebooks);
+  notebooksRef.current = notebooks;
+  const contentsRef = useRef(noteContents);
+  contentsRef.current = noteContents;
+
+  const reload = useCallback(async () => {
+    setNotebooks(await sync.getNotebooks());
+    setNotes(await sync.getNotes());
+  }, []);
+
+  const reset = useCallback(() => {
+    setNotes([]);
+    setNotebooks([]);
+    setNoteContents({});
+    setBacklinks([]);
+  }, []);
+
+  /* ── Background upkeep ── */
+
+  // The sync engine tells us when it has written to IndexedDB behind our back.
+  // Loaded bodies are kept as they are: replacing them here would make the
+  // editor flicker on every poll.
+  useEffect(() => sync.onDataChange(reload), [reload]);
+
+  useEffect(() => {
+    const i = setInterval(() => {
+      if (sync.isOnline()) void sync.fullSync().then(reload).catch(noop);
+    }, FULL_SYNC_MS);
+    return () => clearInterval(i);
+  }, [reload]);
+
+  /* ── The open note's body ── */
+
+  const hasContent = activeNote != null && noteContents[activeNote] !== undefined;
+
+  // Fetched on demand: on a cold start every body is missing, and loading them
+  // all up front would be slow and mostly wasted.
+  useEffect(() => {
+    if (!activeNote || hasContent) return;
+    let cancelled = false;
+    sync
+      .loadNoteContent(activeNote)
+      .then((c) => {
+        if (cancelled) return;
+        setNoteContents((p) => ({ ...p, [activeNote]: c }));
+        const title = notesRef.current.find((n) => n.id === activeNote)?.title || "";
+        searchIndex.setEntry(activeNote, title, c.content);
+      })
+      .catch(() => {
+        if (!cancelled) setNoteContents((p) => ({ ...p, [activeNote]: EMPTY_CONTENT }));
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [activeNote, hasContent]);
+
+  // Hard fallback: an unreachable server must not leave the editor stuck.
+  useEffect(() => {
+    if (!activeNote || hasContent) return;
+    const t = setTimeout(() => {
+      setNoteContents((p) => (p[activeNote] ? p : { ...p, [activeNote]: EMPTY_CONTENT }));
+    }, CONTENT_TIMEOUT_MS);
+    return () => clearTimeout(t);
+  }, [activeNote, hasContent]);
+
+  // Keep the open note fresh across devices.
+  useEffect(() => {
+    if (!user || !activeNote) return;
+    const i = setInterval(() => {
+      if (!sync.isOnline()) return;
+      // Never adopt a response while this note has writes on the way out: it
+      // was requested before them and would undo what was just typed.
+      if (sync.hasPendingWrites(activeNote)) return;
+      sync
+        .loadNoteContent(activeNote, { forceRemote: true })
+        .then((c) => {
+          setNoteContents((p) => {
+            const prev = p[activeNote];
+            if (
+              prev &&
+              prev.content === c.content &&
+              prev.drawingData === c.drawingData &&
+              sameStrokeDoc(prev.drawingStrokes, c.drawingStrokes)
+            )
+              return p;
+            return { ...p, [activeNote]: c };
+          });
+        })
+        .catch(noop);
+    }, ACTIVE_NOTE_POLL_MS);
+    return () => clearInterval(i);
+  }, [user, activeNote]);
+
+  const activeBody = activeNote ? noteContents[activeNote]?.content : undefined;
+  useEffect(() => {
+    if (!activeNote || !user) {
+      setBacklinks([]);
+      return;
+    }
+    let cancelled = false;
+    sync
+      .getBacklinks(activeNote)
+      .then((r) => {
+        if (!cancelled) setBacklinks(r);
+      })
+      .catch(noop);
+    return () => {
+      cancelled = true;
+    };
+  }, [activeNote, user, activeBody]);
+
+  /* ── Notes ── */
+
+  const createNote = useCallback(async (folderId: string) => {
+    const note = await sync.createNote(folderId);
+    setNotes((p) => [note, ...p]);
+    setNoteContents((p) => ({ ...p, [note.id]: EMPTY_CONTENT }));
+    return note;
+  }, []);
+
+  const updateNote = useCallback((id: string, edit: NoteEdit) => {
+    if (edit.title !== undefined) {
+      const title = edit.title;
+      const updatedAt = new Date().toISOString();
+      setNotes((p) => p.map((n) => (n.id === id ? { ...n, title, updatedAt } : n)));
+      void sync.updateNoteTitle(id, title);
+      searchIndex.setEntry(id, title, contentsRef.current[id]?.content);
+    }
+    if (edit.content !== undefined) {
+      const content = edit.content;
+      setNoteContents((p) => ({ ...p, [id]: { ...(p[id] ?? EMPTY_CONTENT), content } }));
+      void sync.updateNoteContent(id, content, edit.links);
+      searchIndex.setEntry(id, notesRef.current.find((n) => n.id === id)?.title || "", content);
+    }
+    if (edit.drawingStrokes !== undefined) {
+      const drawingStrokes = edit.drawingStrokes;
+      setNoteContents((p) => ({ ...p, [id]: { ...(p[id] ?? EMPTY_CONTENT), drawingStrokes } }));
+      void sync.updateNoteDrawing(id, drawingStrokes);
+    }
+  }, []);
+
+  /** Replaces a body wholesale — used when restoring an older version. */
+  const setNoteContent = useCallback((id: string, content: NoteContent) => {
+    setNoteContents((p) => ({ ...p, [id]: content }));
+  }, []);
+
+  const toggleStar = useCallback(async (id: string) => {
+    const starred = await sync.toggleNoteStar(id);
+    setNotes((p) => p.map((n) => (n.id === id ? { ...n, starred } : n)));
+  }, []);
+
+  const trashNote = useCallback(async (id: string) => {
+    await sync.trashNote(id);
+    setNotes((p) => p.map((n) => (n.id === id ? { ...n, trashed: true } : n)));
+  }, []);
+
+  const restoreNote = useCallback(async (id: string) => {
+    await sync.restoreNoteLocal(id);
+    setNotes((p) => p.map((n) => (n.id === id ? { ...n, trashed: false } : n)));
+  }, []);
+
+  const permanentDeleteNote = useCallback(async (id: string) => {
+    await sync.permanentDeleteNoteLocal(id);
+    searchIndex.removeEntry(id);
+    setNotes((p) => p.filter((n) => n.id !== id));
+  }, []);
+
+  const emptyTrash = useCallback(async () => {
+    await sync.emptyTrashLocal();
+    for (const n of notesRef.current) if (n.trashed) searchIndex.removeEntry(n.id);
+    setNotes((p) => p.filter((n) => !n.trashed));
+  }, []);
+
+  const moveNote = useCallback(async (id: string, folderId: string) => {
+    await sync.moveNote(id, folderId);
+    setNotes((p) => p.map((n) => (n.id === id ? { ...n, folderId } : n)));
+  }, []);
+
+  /* ── Notebooks ── */
+
+  const createNotebook = useCallback(async (fields: { name: string; cover: number }) => {
+    const nb = await sync.createNotebook(fields);
+    setNotebooks((p) => [...p, nb]);
+    return nb;
+  }, []);
+
+  const updateNotebook = useCallback(async (id: string, updates: Partial<Notebook>) => {
+    await sync.updateNotebook(id, updates);
+    setNotebooks((p) => p.map((nb) => (nb.id === id ? { ...nb, ...updates } : nb)));
+  }, []);
+
+  /** Deleting a notebook trashes its notes rather than destroying them. */
+  const deleteNotebook = useCallback(async (id: string) => {
+    await sync.deleteNotebookLocal(id);
+    setNotes((p) => p.map((n) => (n.folderId === id ? { ...n, trashed: true } : n)));
+    setNotebooks((p) => p.filter((nb) => nb.id !== id));
+  }, []);
+
+  const reorderNotebooks = useCallback((dragId: string, targetId: string) => {
+    const list = [...notebooksRef.current];
+    const from = list.findIndex((n) => n.id === dragId);
+    const to = list.findIndex((n) => n.id === targetId);
+    if (from < 0 || to < 0 || from === to) return;
+    const [moved] = list.splice(from, 1);
+    if (!moved) return;
+    list.splice(to, 0, moved);
+    const reordered = list.map((n, i) => ({ ...n, sortOrder: i }));
+    setNotebooks(reordered);
+    void sync.reorderNotebooks(reordered.map((n) => n.id));
+  }, []);
+
+  return {
+    notes,
+    notebooks,
+    noteContents,
+    backlinks,
+    reload,
+    reset,
+    createNote,
+    updateNote,
+    setNoteContent,
+    toggleStar,
+    trashNote,
+    restoreNote,
+    permanentDeleteNote,
+    emptyTrash,
+    moveNote,
+    createNotebook,
+    updateNotebook,
+    deleteNotebook,
+    reorderNotebooks,
+  };
+}
+
+const noop = () => {};

frontend/src/hooks/useNotebookDnd.ts

@@ -0,0 +1,48 @@
+import { useCallback, useRef, useState } from "react";
+import type { DragEvent } from "react";
+
+export interface NotebookDnd {
+  /** Notebook currently under the pointer, for the drop indicator. */
+  overId: string | null;
+  onDragStart: (e: DragEvent, id: string) => void;
+  onDragOver: (e: DragEvent, id: string) => void;
+  onDrop: (e: DragEvent, id: string) => void;
+  onDragEnd: () => void;
+}
+
+/**
+ * Drag-to-reorder for the notebook list, shared by the sidebar and the
+ * dashboard so a notebook can be dragged in either place.
+ */
+export function useNotebookDnd(reorder: (dragId: string, targetId: string) => void): NotebookDnd {
+  const [overId, setOverId] = useState<string | null>(null);
+  // The dragged id is not rendered, so a ref avoids a re-render per dragover.
+  const dragId = useRef<string | null>(null);
+
+  const onDragStart = useCallback((e: DragEvent, id: string) => {
+    dragId.current = id;
+    e.dataTransfer.effectAllowed = "move";
+  }, []);
+
+  const onDragOver = useCallback((e: DragEvent, id: string) => {
+    e.preventDefault();
+    if (dragId.current && dragId.current !== id) setOverId(id);
+  }, []);
+
+  const clear = useCallback(() => {
+    dragId.current = null;
+    setOverId(null);
+  }, []);
+
+  const onDrop = useCallback(
+    (e: DragEvent, targetId: string) => {
+      e.preventDefault();
+      const from = dragId.current;
+      if (from && from !== targetId) reorder(from, targetId);
+      clear();
+    },
+    [reorder, clear]
+  );
+
+  return { overId, onDragStart, onDragOver, onDrop, onDragEnd: clear };
+}

frontend/src/hooks/usePwaInstall.ts

@@ -0,0 +1,41 @@
+import { useEffect, useState } from "react";
+
+/** Chrome's non-standard install event. Not in lib.dom, so it is declared here. */
+interface BeforeInstallPromptEvent extends Event {
+  prompt(): Promise<void>;
+  userChoice: Promise<{ outcome: "accepted" | "dismissed" }>;
+}
+
+export interface PwaInstall {
+  /** Non-null only while the browser is willing to show an install prompt. */
+  canInstall: boolean;
+  promptInstall: () => Promise<void>;
+}
+
+/**
+ * Captures the browser's install offer so the app can present it at a sensible
+ * moment instead of letting the browser choose one.
+ */
+export function usePwaInstall(): PwaInstall {
+  const [event, setEvent] = useState<BeforeInstallPromptEvent | null>(null);
+
+  useEffect(() => {
+    const onPrompt = (e: Event) => {
+      e.preventDefault();
+      setEvent(e as BeforeInstallPromptEvent);
+    };
+    window.addEventListener("beforeinstallprompt", onPrompt);
+    return () => window.removeEventListener("beforeinstallprompt", onPrompt);
+  }, []);
+
+  const promptInstall = async () => {
+    if (!event) return;
+    await event.prompt();
+    const { outcome } = await event.userChoice;
+    // The captured event is single-use; drop it either way so the button does
+    // not linger after a decision.
+    if (outcome === "accepted") setEvent(null);
+  };
+
+  return { canInstall: event !== null, promptInstall };
+}

frontend/src/hooks/useResponsive.ts

@@ -0,0 +1,39 @@
+import { useEffect, useState } from "react";
+
+const MOBILE_BREAKPOINT = 768;
+
+export type MobileView = "list" | "editor";
+
+export interface Responsive {
+  isMobile: boolean;
+  sidebarOpen: boolean;
+  setSidebarOpen: (open: boolean) => void;
+  /** On a phone, list and editor share the screen; this says which one has it. */
+  mobileView: MobileView;
+  setMobileView: (view: MobileView) => void;
+}
+
+/**
+ * Tracks whether we are on a phone-sized screen and keeps the sidebar's
+ * open/closed state consistent with it: on a desktop the sidebar is always
+ * available, on a phone it is an overlay that starts closed.
+ */
+export function useResponsive(): Responsive {
+  const [isMobile, setIsMobile] = useState(() => window.innerWidth < MOBILE_BREAKPOINT);
+  const [sidebarOpen, setSidebarOpen] = useState(() => window.innerWidth > MOBILE_BREAKPOINT);
+  const [mobileView, setMobileView] = useState<MobileView>("list");
+
+  useEffect(() => {
+    const onResize = () => {
+      const mobile = window.innerWidth < MOBILE_BREAKPOINT;
+      setIsMobile(mobile);
+      // Growing past the breakpoint must not leave the sidebar hidden with no
+      // way to bring it back.
+      if (!mobile) setSidebarOpen(true);
+    };
+    window.addEventListener("resize", onResize);
+    return () => window.removeEventListener("resize", onResize);
+  }, []);
+
+  return { isMobile, sidebarOpen, setSidebarOpen, mobileView, setMobileView };
+}

frontend/src/hooks/useSearchIndex.ts

@@ -0,0 +1,84 @@
+import { useEffect, useMemo, useRef, useState } from "react";
+
+import * as sync from "../syncEngine";
+import * as searchIndex from "../search";
+import type { NoteMeta, SearchHit, User } from "../types";
+
+const DEBOUNCE_MS = 120;
+/** Refresh visible results every N notes while the backfill is still running. */
+const PROGRESS_EVERY = 10;
+
+export interface SearchState {
+  /** null means "not searching"; an empty array means "searched, found nothing". */
+  results: SearchHit[] | null;
+  /** Excerpt around the match, empty when the note is not a hit. */
+  snippetFor: (id: string) => string;
+}
+
+/**
+ * Full-text search over the local copy of every note.
+ *
+ * The server stores bodies encrypted and cannot index them, so the index is
+ * built here. Bodies normally reach the client only when a note is opened, so
+ * the missing ones are backfilled in the background after login.
+ */
+export function useSearchIndex(user: User | null, notes: NoteMeta[], query: string): SearchState {
+  const [results, setResults] = useState<SearchHit[] | null>(null);
+  const [version, setVersion] = useState(0);
+  const running = useRef(false);
+
+  // Read by the backfill so it sees current titles without being torn down and
+  // restarted every time a note changes.
+  const notesRef = useRef(notes);
+  notesRef.current = notes;
+
+  useEffect(() => {
+    // Waits for the note list: starting before the first sync would find
+    // nothing to fetch and never run again.
+    if (!user || notes.length === 0 || running.current) return;
+    running.current = true;
+    let cancelled = false;
+    const signal = { aborted: false };
+
+    void (async () => {
+      await searchIndex.rebuild();
+      if (!cancelled) setVersion((v) => v + 1);
+      await sync.prefetchAllContent({
+        signal,
+        onProgress: ({ id, content, fetched }) => {
+          const note = notesRef.current.find((n) => n.id === id);
+          searchIndex.setEntry(id, note?.title || "", content);
+          if (fetched % PROGRESS_EVERY === 0 && !cancelled) setVersion((v) => v + 1);
+        },
+      });
+      if (!cancelled) setVersion((v) => v + 1);
+      running.current = false;
+    })();
+
+    return () => {
+      cancelled = true;
+      signal.aborted = true;
+    };
+  }, [user, notes.length]);
+
+  useEffect(() => {
+    const q = query.trim();
+    if (!q) {
+      setResults(null);
+      return;
+    }
+    // Debounced so typing does not re-scan the index on every keystroke.
+    const t = setTimeout(() => setResults(searchIndex.search(q)), DEBOUNCE_MS);
+    return () => clearTimeout(t);
+  }, [query, version]);
+
+  const snippets = useMemo(() => {
+    const m = new Map<string, string>();
+    for (const r of results || []) if (r.snippet) m.set(r.id, r.snippet);
+    return m;
+  }, [results]);
+
+  const snippetFor = useMemo(() => (id: string) => snippets.get(id) || "", [snippets]);
+
+  return { results, snippetFor };
+}

frontend/src/main.jsx

@@ -1,14 +1,17 @@
-import React from 'react'
+import React from "react";
-import ReactDOM from 'react-dom/client'
+import ReactDOM from "react-dom/client";
-import NoteApp from './NoteApp.jsx'
+import NoteApp from "./App.jsx";
 
 // Hide splash screen
 const hideSplash = () => {
-  const splash = document.getElementById('splash');
+  const splash = document.getElementById("splash");
-  if (splash) { splash.classList.add('hide'); setTimeout(() => splash.remove(), 300); }
+  if (splash) {
+    splash.classList.add("hide");
+    setTimeout(() => splash.remove(), 300);
+  }
 };
 
-ReactDOM.createRoot(document.getElementById('root')).render(
+ReactDOM.createRoot(document.getElementById("root")).render(
   <React.StrictMode>
     <NoteApp />
   </React.StrictMode>
@@ -17,17 +20,17 @@ ReactDOM.createRoot(document.getElementById('root')).render(
 setTimeout(hideSplash, 200);
 
 // Register service worker
-if ('serviceWorker' in navigator) {
+if ("serviceWorker" in navigator) {
-  window.addEventListener('load', async () => {
+  window.addEventListener("load", async () => {
     try {
       // Use the page's base URL as scope so it works behind any reverse proxy path
-      const swUrl = new URL('./sw.js', window.location.href).href;
+      const swUrl = new URL("./sw.js", window.location.href).href;
-      const scope = new URL('./', window.location.href).href;
+      const scope = new URL("./", window.location.href).href;
       const reg = await navigator.serviceWorker.register(swUrl, { scope });
-      console.log('[SW] Registered, scope:', reg.scope);
+      console.log("[SW] Registered, scope:", reg.scope);
       setInterval(() => reg.update(), 60 * 60 * 1000);
     } catch (err) {
-      console.warn('[SW] Registration failed:', err);
+      console.warn("[SW] Registration failed:", err);
     }
   });
 }

frontend/src/offlineStore.js

@@ -1,204 +0,0 @@
-/**
- * InkNote Offline Store — IndexedDB local-first storage
- * 
- * All reads/writes go here first (instant, works offline).
- * Sync engine flushes changes to server when online.
- */
-
-const DB_NAME = 'inknote';
-const DB_VERSION = 2;
-
-let db = null;
-
-function open() {
-  return new Promise((resolve, reject) => {
-    if (db) return resolve(db);
-    const req = indexedDB.open(DB_NAME, DB_VERSION);
-
-    req.onupgradeneeded = (e) => {
-      const d = e.target.result;
-
-      // Notebooks store
-      if (!d.objectStoreNames.contains('notebooks')) {
-        const nb = d.createObjectStore('notebooks', { keyPath: 'id' });
-        nb.createIndex('sortOrder', 'sortOrder');
-      }
-
-      // Notes metadata store
-      if (!d.objectStoreNames.contains('notes')) {
-        const n = d.createObjectStore('notes', { keyPath: 'id' });
-        n.createIndex('folderId', 'folderId');
-        n.createIndex('trashed', 'trashed');
-        n.createIndex('updatedAt', 'updatedAt');
-      }
-
-      // Note content store (separate for lazy loading)
-      if (!d.objectStoreNames.contains('noteContents')) {
-        d.createObjectStore('noteContents', { keyPath: 'id' });
-      }
-
-      // Sync queue — pending changes to push to server
-      if (!d.objectStoreNames.contains('syncQueue')) {
-        const sq = d.createObjectStore('syncQueue', { keyPath: 'queueId', autoIncrement: true });
-        sq.createIndex('entityId', 'entityId');
-        sq.createIndex('timestamp', 'timestamp');
-      }
-
-      // Key-value meta store (token, user, last sync time, etc)
-      if (!d.objectStoreNames.contains('meta')) {
-        d.createObjectStore('meta', { keyPath: 'key' });
-      }
-    };
-
-    req.onsuccess = (e) => { db = e.target.result; resolve(db); };
-    req.onerror = (e) => reject(e.target.error);
-  });
-}
-
-// ─── Generic helpers ───
-async function tx(stores, mode, fn) {
-  const d = await open();
-  return new Promise((resolve, reject) => {
-    const t = d.transaction(stores, mode);
-    const result = fn(t);
-    t.oncomplete = () => resolve(result._value);
-    t.onerror = (e) => reject(e.target.error);
-  });
-}
-
-function reqToPromise(req) {
-  return new Promise((res, rej) => { req.onsuccess = () => res(req.result); req.onerror = (e) => rej(e.target.error); });
-}
-
-// ─── Meta (key-value) ───
-export async function getMeta(key) {
-  const d = await open();
-  const r = await reqToPromise(d.transaction('meta', 'readonly').objectStore('meta').get(key));
-  return r?.value ?? null;
-}
-
-export async function setMeta(key, value) {
-  const d = await open();
-  await reqToPromise(d.transaction('meta', 'readwrite').objectStore('meta').put({ key, value }));
-}
-
-export async function deleteMeta(key) {
-  const d = await open();
-  await reqToPromise(d.transaction('meta', 'readwrite').objectStore('meta').delete(key));
-}
-
-// ─── Notebooks ───
-export async function getAllNotebooks() {
-  const d = await open();
-  const all = await reqToPromise(d.transaction('notebooks', 'readonly').objectStore('notebooks').getAll());
-  return all.sort((a, b) => (a.sortOrder || 0) - (b.sortOrder || 0));
-}
-
-export async function putNotebook(nb) {
-  const d = await open();
-  await reqToPromise(d.transaction('notebooks', 'readwrite').objectStore('notebooks').put(nb));
-}
-
-export async function putNotebooks(list) {
-  const d = await open();
-  const t = d.transaction('notebooks', 'readwrite');
-  const s = t.objectStore('notebooks');
-  for (const nb of list) s.put(nb);
-  return new Promise((res, rej) => { t.oncomplete = res; t.onerror = rej; });
-}
-
-export async function deleteNotebook(id) {
-  const d = await open();
-  await reqToPromise(d.transaction('notebooks', 'readwrite').objectStore('notebooks').delete(id));
-}
-
-export async function clearNotebooks() {
-  const d = await open();
-  await reqToPromise(d.transaction('notebooks', 'readwrite').objectStore('notebooks').clear());
-}
-
-// ─── Notes (metadata) ───
-export async function getAllNotes() {
-  const d = await open();
-  return reqToPromise(d.transaction('notes', 'readonly').objectStore('notes').getAll());
-}
-
-export async function getNote(id) {
-  const d = await open();
-  return reqToPromise(d.transaction('notes', 'readonly').objectStore('notes').get(id));
-}
-
-export async function putNote(note) {
-  const d = await open();
-  await reqToPromise(d.transaction('notes', 'readwrite').objectStore('notes').put(note));
-}
-
-export async function putNotes(list) {
-  const d = await open();
-  const t = d.transaction('notes', 'readwrite');
-  const s = t.objectStore('notes');
-  for (const n of list) s.put(n);
-  return new Promise((res, rej) => { t.oncomplete = res; t.onerror = rej; });
-}
-
-export async function deleteNote(id) {
-  const d = await open();
-  const t = d.transaction(['notes', 'noteContents'], 'readwrite');
-  t.objectStore('notes').delete(id);
-  t.objectStore('noteContents').delete(id);
-  return new Promise((res, rej) => { t.oncomplete = res; t.onerror = rej; });
-}
-
-export async function clearNotes() {
-  const d = await open();
-  const t = d.transaction(['notes'], 'readwrite');
-  t.objectStore('notes').clear();
-  return new Promise((res, rej) => { t.oncomplete = res; t.onerror = rej; });
-}
-
-// ─── Note content (lazy loaded) ───
-export async function getNoteContent(id) {
-  const d = await open();
-  return reqToPromise(d.transaction('noteContents', 'readonly').objectStore('noteContents').get(id));
-}
-
-export async function putNoteContent(id, content, drawingData) {
-  const d = await open();
-  await reqToPromise(d.transaction('noteContents', 'readwrite').objectStore('noteContents').put({ id, content, drawingData }));
-}
-
-// ─── Sync Queue ───
-export async function enqueue(action) {
-  const d = await open();
-  const entry = { ...action, timestamp: Date.now() };
-  await reqToPromise(d.transaction('syncQueue', 'readwrite').objectStore('syncQueue').add(entry));
-}
-
-export async function peekQueue(limit = 50) {
-  const d = await open();
-  return reqToPromise(d.transaction('syncQueue', 'readonly').objectStore('syncQueue').getAll(null, limit));
-}
-
-export async function dequeue(queueId) {
-  const d = await open();
-  await reqToPromise(d.transaction('syncQueue', 'readwrite').objectStore('syncQueue').delete(queueId));
-}
-
-export async function clearQueue() {
-  const d = await open();
-  await reqToPromise(d.transaction('syncQueue', 'readwrite').objectStore('syncQueue').clear());
-}
-
-export async function getQueueSize() {
-  const d = await open();
-  return reqToPromise(d.transaction('syncQueue', 'readonly').objectStore('syncQueue').count());
-}
-
-// ─── Full wipe (for logout) ───
-export async function clearAll() {
-  const d = await open();
-  const stores = ['notebooks', 'notes', 'noteContents', 'syncQueue', 'meta'];
-  const t = d.transaction(stores, 'readwrite');
-  stores.forEach((s) => t.objectStore(s).clear());
-  return new Promise((res, rej) => { t.oncomplete = res; t.onerror = rej; });
-}

frontend/src/offlineStore.test.ts

@@ -0,0 +1,175 @@
+import { describe, it, expect, beforeEach } from "vitest";
+
+import * as db from "./offlineStore";
+import type { NoteMeta, Notebook } from "./types";
+
+const note = (id: string, over: Partial<NoteMeta> = {}): NoteMeta => ({
+  id,
+  title: `Note ${id}`,
+  folderId: "nb1",
+  starred: false,
+  trashed: false,
+  createdAt: "2026-01-01T00:00:00.000Z",
+  updatedAt: "2026-01-01T00:00:00.000Z",
+  ...over,
+});
+
+const notebook = (id: string, sortOrder = 0): Notebook => ({ id, name: `NB ${id}`, cover: 0, sortOrder });
+
+beforeEach(async () => {
+  await db.clearAll();
+});
+
+describe("notes", () => {
+  it("stores and reads back a note", async () => {
+    await db.putNote(note("a"));
+    expect(await db.getNote("a")).toMatchObject({ id: "a", title: "Note a" });
+  });
+
+  it("returns undefined for a note that does not exist", async () => {
+    expect(await db.getNote("nope")).toBeUndefined();
+  });
+
+  it("writes a batch in one transaction", async () => {
+    await db.putNotes([note("a"), note("b"), note("c")]);
+    expect((await db.getAllNotes()).length).toBe(3);
+  });
+
+  it("deleting a note also drops its body, leaving nothing orphaned", async () => {
+    await db.putNote(note("a"));
+    await db.putNoteContent("a", "content", null);
+    await db.deleteNote("a");
+    expect(await db.getNote("a")).toBeUndefined();
+    expect(await db.getNoteContent("a")).toBeUndefined();
+  });
+});
+
+describe("note content", () => {
+  it("keeps content, drawing and revision together", async () => {
+    const strokes = {
+      v: 1,
+      w: 1200,
+      h: 1600,
+      strokes: [{ t: "pen" as const, c: "#fff", s: 5, p: [0, 0, 1, 1] }],
+    };
+    await db.putNoteContent("a", "body", null, strokes, "2026-02-02T00:00:00.000Z");
+    const got = await db.getNoteContent("a");
+    expect(got?.content).toBe("body");
+    expect(got?.drawingStrokes?.strokes.length).toBe(1);
+    expect(got?.updatedAt).toBe("2026-02-02T00:00:00.000Z");
+  });
+
+  it("defaults the drawing fields rather than leaving them undefined", async () => {
+    await db.putNoteContent("a", "body", null);
+    const got = await db.getNoteContent("a");
+    expect(got?.drawingStrokes).toBeNull();
+    expect(got?.updatedAt).toBeNull();
+  });
+
+  it("overwrites an existing body", async () => {
+    await db.putNoteContent("a", "first", null);
+    await db.putNoteContent("a", "second", null);
+    expect((await db.getNoteContent("a"))?.content).toBe("second");
+  });
+});
+
+describe("notebooks", () => {
+  it("returns notebooks in sort order, not insertion order", async () => {
+    await db.putNotebooks([notebook("c", 2), notebook("a", 0), notebook("b", 1)]);
+    expect((await db.getAllNotebooks()).map((n) => n.id)).toEqual(["a", "b", "c"]);
+  });
+});
+
+describe("sync queue", () => {
+  it("preserves insertion order", async () => {
+    await db.enqueue({ action: "first", data: {} });
+    await db.enqueue({ action: "second", data: {} });
+    expect((await db.peekQueue()).map((e) => e.action)).toEqual(["first", "second"]);
+  });
+
+  it("counts what is waiting", async () => {
+    await db.enqueue({ action: "a", data: {} });
+    await db.enqueue({ action: "b", data: {} });
+    expect(await db.getQueueSize()).toBe(2);
+  });
+
+  it("removes only the dequeued entry", async () => {
+    await db.enqueue({ action: "keep", data: {} });
+    await db.enqueue({ action: "drop", data: {} });
+    const [, second] = await db.peekQueue();
+    await db.dequeue(second!.queueId);
+    expect((await db.peekQueue()).map((e) => e.action)).toEqual(["keep"]);
+  });
+
+  it("records a failed attempt without losing the entry — the bug that silently ate offline edits", async () => {
+    await db.enqueue({ action: "updateNote", data: { id: "a" } });
+    const [entry] = await db.peekQueue();
+    await db.updateQueueEntry(entry!.queueId, { attempts: 1, lastError: "boom" });
+
+    const [updated] = await db.peekQueue();
+    expect(updated!.attempts).toBe(1);
+    expect(updated!.lastError).toBe("boom");
+    expect(updated!.action).toBe("updateNote");
+    expect(updated!.data).toEqual({ id: "a" });
+  });
+
+  it("ignores an update for an entry that is already gone", async () => {
+    await expect(db.updateQueueEntry(9999, { attempts: 1 })).resolves.toBeUndefined();
+  });
+});
+
+describe("attachments", () => {
+  /* jsdom's Blob is a stub without `arrayBuffer`, and fake-indexeddb's
+   * structured clone flattens it to `{}` — so real Blob fidelity cannot be
+   * asserted here. A byte array clones faithfully and still exercises the
+   * store's own logic; that images survive a round trip through a real browser
+   * is covered by the end-to-end suite instead. */
+  it("round-trips binary payloads", async () => {
+    const bytes = new Uint8Array([1, 2, 3, 250]);
+    await db.putAttachmentBlob("att1", bytes as unknown as Blob);
+    const got = (await db.getAttachmentBlob("att1")) as unknown as Uint8Array;
+    expect(got).not.toBeNull();
+    expect(Array.from(got)).toEqual([1, 2, 3, 250]);
+  });
+
+  it("returns null for an attachment that was never cached", async () => {
+    expect(await db.getAttachmentBlob("missing")).toBeNull();
+  });
+});
+
+describe("meta", () => {
+  it("stores arbitrary values", async () => {
+    await db.setMeta("user", { id: "u1", username: "marc" });
+    expect(await db.getMeta("user")).toEqual({ id: "u1", username: "marc" });
+  });
+
+  it("returns null for an unset key", async () => {
+    expect(await db.getMeta("nothing")).toBeNull();
+  });
+
+  it("deletes a key", async () => {
+    await db.setMeta("token", "abc");
+    await db.deleteMeta("token");
+    expect(await db.getMeta("token")).toBeNull();
+  });
+});
+
+describe("clearAll", () => {
+  it("wipes every store, as logout must", async () => {
+    await db.putNote(note("a"));
+    await db.putNoteContent("a", "body", null);
+    await db.putNotebook(notebook("nb1"));
+    await db.enqueue({ action: "x", data: {} });
+    await db.setMeta("token", "abc");
+    await db.putAttachmentBlob("att", new Blob(["x"]));
+
+    await db.clearAll();
+
+    expect(await db.getAllNotes()).toEqual([]);
+    expect(await db.getNoteContent("a")).toBeUndefined();
+    expect(await db.getAllNotebooks()).toEqual([]);
+    expect(await db.getQueueSize()).toBe(0);
+    expect(await db.getMeta("token")).toBeNull();
+    expect(await db.getAttachmentBlob("att")).toBeNull();
+  });
+});

frontend/src/offlineStore.ts

@@ -0,0 +1,245 @@
+/**
+ * InkNote Offline Store — IndexedDB local-first storage.
+ *
+ * All reads and writes go here first, so the app works offline; the sync engine
+ * pushes queued changes to the server when a connection is available.
+ */
+
+import type { NoteMeta, NoteContent, Notebook, StrokeDoc, QueueEntry } from "./types";
+
+const DB_NAME = "inknote";
+const DB_VERSION = 3;
+
+type StoreName = "notebooks" | "notes" | "noteContents" | "syncQueue" | "meta" | "attachments";
+
+let db: IDBDatabase | null = null;
+
+function open(): Promise<IDBDatabase> {
+  return new Promise((resolve, reject) => {
+    if (db) return resolve(db);
+    const req = indexedDB.open(DB_NAME, DB_VERSION);
+
+    req.onupgradeneeded = (e) => {
+      const d = (e.target as IDBOpenDBRequest).result;
+
+      if (!d.objectStoreNames.contains("notebooks")) {
+        const nb = d.createObjectStore("notebooks", { keyPath: "id" });
+        nb.createIndex("sortOrder", "sortOrder");
+      }
+
+      if (!d.objectStoreNames.contains("notes")) {
+        const n = d.createObjectStore("notes", { keyPath: "id" });
+        n.createIndex("folderId", "folderId");
+        n.createIndex("trashed", "trashed");
+        n.createIndex("updatedAt", "updatedAt");
+      }
+
+      // Bodies live apart from metadata so the note list stays cheap to load.
+      if (!d.objectStoreNames.contains("noteContents")) {
+        d.createObjectStore("noteContents", { keyPath: "id" });
+      }
+
+      if (!d.objectStoreNames.contains("syncQueue")) {
+        const sq = d.createObjectStore("syncQueue", { keyPath: "queueId", autoIncrement: true });
+        sq.createIndex("entityId", "entityId");
+        sq.createIndex("timestamp", "timestamp");
+      }
+
+      if (!d.objectStoreNames.contains("meta")) {
+        d.createObjectStore("meta", { keyPath: "key" });
+      }
+
+      // Attachment bytes, so images render offline and download only once.
+      if (!d.objectStoreNames.contains("attachments")) {
+        d.createObjectStore("attachments", { keyPath: "id" });
+      }
+    };
+
+    req.onsuccess = (e) => {
+      db = (e.target as IDBOpenDBRequest).result;
+      resolve(db);
+    };
+    req.onerror = (e) => reject((e.target as IDBOpenDBRequest).error);
+  });
+}
+
+function reqToPromise<T>(req: IDBRequest<T>): Promise<T> {
+  return new Promise((res, rej) => {
+    req.onsuccess = () => res(req.result);
+    req.onerror = () => rej(req.error);
+  });
+}
+
+/** Resolves when the whole transaction commits, not just one request. */
+function txDone(t: IDBTransaction): Promise<void> {
+  return new Promise((res, rej) => {
+    t.oncomplete = () => res();
+    t.onerror = () => rej(t.error);
+    t.onabort = () => rej(t.error ?? new Error("Transaction aborted"));
+  });
+}
+
+async function store(name: StoreName, mode: IDBTransactionMode): Promise<IDBObjectStore> {
+  const d = await open();
+  return d.transaction(name, mode).objectStore(name);
+}
+
+/* ─── Meta (key-value) ─── */
+export async function getMeta<T = unknown>(key: string): Promise<T | null> {
+  const s = await store("meta", "readonly");
+  const r = await reqToPromise<{ key: string; value: T } | undefined>(s.get(key));
+  return r?.value ?? null;
+}
+
+export async function setMeta(key: string, value: unknown): Promise<void> {
+  const s = await store("meta", "readwrite");
+  await reqToPromise(s.put({ key, value }));
+}
+
+export async function deleteMeta(key: string): Promise<void> {
+  const s = await store("meta", "readwrite");
+  await reqToPromise(s.delete(key));
+}
+
+/* ─── Notebooks ─── */
+export async function getAllNotebooks(): Promise<Notebook[]> {
+  const s = await store("notebooks", "readonly");
+  const all = await reqToPromise<Notebook[]>(s.getAll());
+  return all.sort((a, b) => (a.sortOrder || 0) - (b.sortOrder || 0));
+}
+
+export async function putNotebook(nb: Notebook): Promise<void> {
+  const s = await store("notebooks", "readwrite");
+  await reqToPromise(s.put(nb));
+}
+
+export async function putNotebooks(list: Notebook[]): Promise<void> {
+  const d = await open();
+  const t = d.transaction("notebooks", "readwrite");
+  const s = t.objectStore("notebooks");
+  for (const nb of list) s.put(nb);
+  return txDone(t);
+}
+
+export async function deleteNotebook(id: string): Promise<void> {
+  const s = await store("notebooks", "readwrite");
+  await reqToPromise(s.delete(id));
+}
+
+export async function clearNotebooks(): Promise<void> {
+  const s = await store("notebooks", "readwrite");
+  await reqToPromise(s.clear());
+}
+
+/* ─── Notes (metadata) ─── */
+export async function getAllNotes(): Promise<NoteMeta[]> {
+  const s = await store("notes", "readonly");
+  return reqToPromise<NoteMeta[]>(s.getAll());
+}
+
+export async function getNote(id: string): Promise<NoteMeta | undefined> {
+  const s = await store("notes", "readonly");
+  return reqToPromise<NoteMeta | undefined>(s.get(id));
+}
+
+export async function putNote(note: NoteMeta): Promise<void> {
+  const s = await store("notes", "readwrite");
+  await reqToPromise(s.put(note));
+}
+
+export async function putNotes(list: NoteMeta[]): Promise<void> {
+  const d = await open();
+  const t = d.transaction("notes", "readwrite");
+  const s = t.objectStore("notes");
+  for (const n of list) s.put(n);
+  return txDone(t);
+}
+
+export async function deleteNote(id: string): Promise<void> {
+  const d = await open();
+  const t = d.transaction(["notes", "noteContents"], "readwrite");
+  t.objectStore("notes").delete(id);
+  t.objectStore("noteContents").delete(id);
+  return txDone(t);
+}
+
+export async function clearNotes(): Promise<void> {
+  const s = await store("notes", "readwrite");
+  await reqToPromise(s.clear());
+}
+
+/* ─── Note content (lazily loaded) ─── */
+export async function getNoteContent(id: string): Promise<(NoteContent & { id: string }) | undefined> {
+  const s = await store("noteContents", "readonly");
+  return reqToPromise<(NoteContent & { id: string }) | undefined>(s.get(id));
+}
+
+/**
+ * `updatedAt` records which server revision this copy came from, so a background
+ * prefetch can tell a stale cached body from an up-to-date one.
+ */
+export async function putNoteContent(
+  id: string,
+  content: string,
+  drawingData: string | null,
+  drawingStrokes: StrokeDoc | null = null,
+  updatedAt: string | null = null
+): Promise<void> {
+  const s = await store("noteContents", "readwrite");
+  await reqToPromise(s.put({ id, content, drawingData, drawingStrokes, updatedAt }));
+}
+
+/* ─── Attachments (binary cache) ─── */
+export async function getAttachmentBlob(id: string): Promise<Blob | null> {
+  const s = await store("attachments", "readonly");
+  const r = await reqToPromise<{ id: string; blob: Blob } | undefined>(s.get(id));
+  return r?.blob ?? null;
+}
+
+export async function putAttachmentBlob(id: string, blob: Blob): Promise<void> {
+  const s = await store("attachments", "readwrite");
+  await reqToPromise(s.put({ id, blob, cachedAt: Date.now() }));
+}
+
+/* ─── Sync queue ─── */
+export async function enqueue(action: { action: string; data: Record<string, unknown> }): Promise<void> {
+  const s = await store("syncQueue", "readwrite");
+  await reqToPromise(s.add({ ...action, timestamp: Date.now() }));
+}
+
+export async function peekQueue(limit = 50): Promise<QueueEntry[]> {
+  const s = await store("syncQueue", "readonly");
+  return reqToPromise<QueueEntry[]>(s.getAll(null, limit));
+}
+
+export async function dequeue(queueId: number): Promise<void> {
+  const s = await store("syncQueue", "readwrite");
+  await reqToPromise(s.delete(queueId));
+}
+
+/** Records a failed attempt so a retried entry can eventually be given up on. */
+export async function updateQueueEntry(queueId: number, patch: Partial<QueueEntry>): Promise<void> {
+  const s = await store("syncQueue", "readwrite");
+  const entry = await reqToPromise<QueueEntry | undefined>(s.get(queueId));
+  if (!entry) return;
+  await reqToPromise(s.put({ ...entry, ...patch }));
+}
+
+export async function clearQueue(): Promise<void> {
+  const s = await store("syncQueue", "readwrite");
+  await reqToPromise(s.clear());
+}
+
+export async function getQueueSize(): Promise<number> {
+  const s = await store("syncQueue", "readonly");
+  return reqToPromise<number>(s.count());
+}
+
+/* ─── Full wipe (on logout) ─── */
+export async function clearAll(): Promise<void> {
+  const d = await open();
+  const stores: StoreName[] = ["notebooks", "notes", "noteContents", "syncQueue", "meta", "attachments"];
+  const t = d.transaction(stores, "readwrite");
+  for (const s of stores) t.objectStore(s).clear();
+  return txDone(t);
+}

frontend/src/search.test.ts

@@ -0,0 +1,108 @@
+import { describe, it, expect, beforeEach } from "vitest";
+
+import * as search from "./search";
+import { serializeNoteContent } from "./editor/content";
+
+const body = (text: string) =>
+  serializeNoteContent({
+    type: "doc",
+    content: [{ type: "paragraph", content: [{ type: "text", text }] }],
+  });
+
+const seed = () => {
+  search.removeEntry("a");
+  search.removeEntry("b");
+  search.removeEntry("c");
+  search.setEntry("a", "Haushalt", body("Der Kühlschrank braucht eine neue Dichtung."));
+  search.setEntry("b", "Finanzen", body("Steuererklärung abgeben, Belege liegen im Ordner."));
+  search.setEntry("c", "Dichtung", body("Nur der Titel enthält das Wort."));
+};
+
+beforeEach(seed);
+
+describe("search", () => {
+  it("returns null for an empty query, meaning 'no search'", () => {
+    expect(search.search("")).toBeNull();
+    expect(search.search("   ")).toBeNull();
+  });
+
+  it("finds a word that appears only in the body", () => {
+    const hits = search.search("Belege");
+    expect(hits?.map((h) => h.id)).toEqual(["b"]);
+  });
+
+  it("ranks a title match above a body match", () => {
+    const hits = search.search("Dichtung");
+    expect(hits?.map((h) => h.id)).toEqual(["c", "a"]);
+  });
+
+  it("requires every term to match", () => {
+    expect(search.search("Belege Ordner")?.map((h) => h.id)).toEqual(["b"]);
+    expect(search.search("Belege Kühlschrank")).toEqual([]);
+  });
+
+  it("ignores case", () => {
+    expect(search.search("BELEGE")?.map((h) => h.id)).toEqual(["b"]);
+  });
+
+  it("ignores diacritics, so an ASCII keyboard still finds umlauts", () => {
+    expect(search.search("kuhlschrank")?.map((h) => h.id)).toEqual(["a"]);
+    expect(search.search("Steuererklarung")?.map((h) => h.id)).toEqual(["b"]);
+  });
+
+  it("returns a snippet around the match", () => {
+    const hit = search.search("Dichtung")?.find((h) => h.id === "a");
+    expect(hit?.snippet).toMatch(/Dichtung/);
+  });
+
+  it("respects the result limit", () => {
+    for (let i = 0; i < 30; i++) search.setEntry(`x${i}`, `Note ${i}`, body("common word"));
+    expect(search.search("common", { limit: 5 })?.length).toBe(5);
+    for (let i = 0; i < 30; i++) search.removeEntry(`x${i}`);
+  });
+
+  it("stops matching a note once it is removed from the index", () => {
+    expect(search.search("Belege")?.length).toBe(1);
+    search.removeEntry("b");
+    expect(search.search("Belege")).toEqual([]);
+  });
+
+  it("reflects an updated body immediately", () => {
+    search.setEntry("a", "Haushalt", body("Völlig anderer Inhalt jetzt."));
+    expect(search.search("Kühlschrank")).toEqual([]);
+    expect(search.search("anderer")?.map((h) => h.id)).toEqual(["a"]);
+  });
+});
+
+describe("contentToText", () => {
+  it("reads a v2 document", () => {
+    expect(search.contentToText(body("hello world"))).toBe("hello world");
+  });
+
+  it("reads a v1 body, HTML and task list alike", () => {
+    const v1 = JSON.stringify({
+      html: "<p>legacy <b>text</b></p>",
+      tasks: [{ id: "t", text: "buy milk", done: false }],
+    });
+    const text = search.contentToText(v1);
+    expect(text).toContain("legacy");
+    expect(text).toContain("buy milk");
+  });
+
+  it("does not execute or leak markup from a v1 body", () => {
+    const text = search.contentToText(JSON.stringify({ html: "<p>safe</p><script>bad()</script>" }));
+    expect(text).toContain("safe");
+    expect(text).not.toContain("<script>");
+  });
+
+  it("survives content that is not valid JSON", () => {
+    expect(() => search.contentToText("<p>bare html</p>")).not.toThrow();
+    expect(search.contentToText("<p>bare html</p>")).toContain("bare html");
+  });
+
+  it("returns an empty string for empty input", () => {
+    expect(search.contentToText(null)).toBe("");
+    expect(search.contentToText(undefined)).toBe("");
+    expect(search.contentToText("")).toBe("");
+  });
+});

frontend/src/search.ts

@@ -0,0 +1,133 @@
+/**
+ * Local full-text search.
+ *
+ * The server stores note bodies encrypted and deliberately keeps no plaintext
+ * index — so searching has to happen on the client, over the copy already in
+ * IndexedDB. That also means search keeps working offline.
+ *
+ * The index is a plain in-memory map. For a personal note collection that is
+ * both fast enough and far simpler than a real inverted index: matching a few
+ * thousand strings costs well under a frame.
+ */
+
+import * as db from "./offlineStore";
+import { docToText } from "./editor/content";
+import type { SearchHit } from "./types";
+
+interface IndexEntry {
+  /** Normalised title, for matching. */
+  title: string;
+  /** Normalised body text, for matching. */
+  text: string;
+  /** Original body text, for building the snippet shown to the user. */
+  raw: string;
+}
+
+const _index = new Map<string, IndexEntry>();
+
+/** Lowercases and strips diacritics, so `kuhlschrank` matches `Kühlschrank`. */
+const normalize = (s: unknown): string =>
+  String(s ?? "")
+    .toLowerCase()
+    .normalize("NFKD")
+    .replace(/\p{Diacritic}/gu, "");
+
+/** Plain text of a stored note body, whatever format it is in. */
+export function contentToText(raw: string | null | undefined): string {
+  if (!raw) return "";
+  let parsed: unknown = null;
+  try {
+    parsed = JSON.parse(raw);
+  } catch {
+    parsed = null;
+  }
+
+  const obj = parsed as { v?: number; doc?: unknown; html?: unknown; tasks?: unknown } | null;
+  if (obj && obj.v === 2 && obj.doc) return docToText(obj.doc, 20000);
+
+  // v1 — HTML plus a detached task list.
+  const html = typeof obj?.html === "string" ? obj.html : raw;
+  const el = document.createElement("div");
+  el.innerHTML = html;
+  const tasks = Array.isArray(obj?.tasks)
+    ? (obj.tasks as Array<{ text?: string }>).map((t) => t.text ?? "").join(" ")
+    : "";
+  return `${el.textContent || ""} ${tasks}`.replace(/\s+/g, " ").trim();
+}
+
+export function setEntry(id: string, title: string, content?: string | null): void {
+  const raw = contentToText(content);
+  _index.set(id, { title: normalize(title), text: normalize(raw), raw });
+}
+
+export function removeEntry(id: string): void {
+  _index.delete(id);
+}
+
+export function size(): number {
+  return _index.size;
+}
+
+/** Builds the index from whatever is cached locally. */
+export async function rebuild(): Promise<number> {
+  const notes = await db.getAllNotes();
+  _index.clear();
+  for (const n of notes) {
+    const c = await db.getNoteContent(n.id);
+    setEntry(n.id, n.title, c?.content);
+  }
+  return _index.size;
+}
+
+/**
+ * Ranked matches for a query.
+ *
+ * All terms must appear (AND). Title matches outrank body matches so that
+ * searching for a note by name still puts that note first. Returns `null` for
+ * an empty query, which callers read as "no search, show the plain list".
+ */
+export function search(query: string, { limit = 200 }: { limit?: number } = {}): SearchHit[] | null {
+  const terms = normalize(query).split(/\s+/).filter(Boolean);
+  if (terms.length === 0) return null;
+
+  const hits: Array<{ id: string; score: number; entry: IndexEntry }> = [];
+  for (const [id, entry] of _index) {
+    let score = 0;
+    let matchedAll = true;
+    for (const term of terms) {
+      const inTitle = entry.title.includes(term);
+      const inText = entry.text.includes(term);
+      if (!inTitle && !inText) {
+        matchedAll = false;
+        break;
+      }
+      if (inTitle) score += entry.title.startsWith(term) ? 12 : 8;
+      if (inText) score += 1;
+    }
+    if (matchedAll) hits.push({ id, score, entry });
+  }
+
+  hits.sort((a, b) => b.score - a.score);
+  return hits.slice(0, limit).map(({ id, score, entry }) => ({
+    id,
+    score,
+    snippet: snippetFor(entry, terms),
+  }));
+}
+
+/** A short excerpt around the first matching term, for the results list. */
+function snippetFor(entry: IndexEntry, terms: string[], radius = 60): string {
+  const text = entry.raw;
+  if (!text) return "";
+  const haystack = normalize(text);
+  let at = -1;
+  for (const term of terms) {
+    const i = haystack.indexOf(term);
+    if (i !== -1 && (at === -1 || i < at)) at = i;
+  }
+  if (at === -1) return text.slice(0, radius * 2).trim();
+
+  const start = Math.max(0, at - radius);
+  const end = Math.min(text.length, at + radius);
+  return `${start > 0 ? "…" : ""}${text.slice(start, end).trim()}${end < text.length ? "…" : ""}`;
+}

frontend/src/syncEngine.js

@@ -1,369 +0,0 @@
-/**
- * InkNote Sync Engine v2 — online-first, offline-fallback
- *
- * When ONLINE:  Server call → cache to IndexedDB (server IDs everywhere)
- * When OFFLINE: IndexedDB + queue → flush on reconnect
- */
-
-import * as db from './offlineStore.js';
-const REQUEST_TIMEOUT_MS = 12000;
-
-const DEVICE_ID = (() => {
-  try {
-    let d = localStorage.getItem('inknote_device');
-    if (!d) { d = 'dev_' + Math.random().toString(36).slice(2, 10); localStorage.setItem('inknote_device', d); }
-    return d;
-  } catch { return 'dev_' + Math.random().toString(36).slice(2, 10); }
-})();
-
-/* ─── API helper ─── */
-const api = {
-  base: '/api',
-  token: null,
-  async req(method, path, body) {
-    const controller = new AbortController();
-    const timeoutId = setTimeout(() => controller.abort(), REQUEST_TIMEOUT_MS);
-    const opts = { method, headers: { 'Content-Type': 'application/json', 'X-Device-Id': DEVICE_ID }, signal: controller.signal };
-    if (this.token) opts.headers['Authorization'] = 'Bearer ' + this.token;
-    if (body) opts.body = JSON.stringify(body);
-    try {
-      let r;
-      try {
-        r = await fetch(this.base + path, opts);
-      } catch (err) {
-        if (err?.name === 'AbortError') throw new Error('TIMEOUT');
-        throw new Error('NETWORK');
-      }
-      if (r.status === 401) { this.token = null; try { localStorage.removeItem('inknote_token'); } catch {} throw new Error('AUTH'); }
-      let data = {};
-      try { data = await r.json(); } catch {}
-      if (!r.ok) throw new Error(data.error || 'Request failed');
-      return data;
-    } finally {
-      clearTimeout(timeoutId);
-    }
-  },
-  get(p) { return this.req('GET', p); },
-  post(p, b) { return this.req('POST', p, b); },
-  put(p, b) { return this.req('PUT', p, b); },
-  del(p) { return this.req('DELETE', p); },
-};
-
-/* ─── Online status ─── */
-let _online = navigator.onLine;
-window.addEventListener('online', () => { _online = true; notifyStatus('syncing'); flushQueue().then(() => fullSync()).catch(() => {}); });
-window.addEventListener('offline', () => { _online = false; notifyStatus('offline'); });
-export function isOnline() { return _online; }
-
-/* ─── Status ─── */
-let _syncStatus = 'synced';
-let _statusCbs = [];
-let _dataCbs = [];
-function notifyStatus(s) { _syncStatus = s; _statusCbs.forEach(fn => fn(s)); }
-export function onSyncStatus(fn) { _statusCbs.push(fn); fn(_syncStatus); return () => { _statusCbs = _statusCbs.filter(f => f !== fn); }; }
-function notifyData(t, d) { _dataCbs.forEach(fn => fn(t, d)); }
-export function onDataChange(fn) { _dataCbs.push(fn); return () => { _dataCbs = _dataCbs.filter(f => f !== fn); }; }
-
-/* ─── Auth ─── */
-export async function login(email, password) {
-  const data = await api.post('/auth/login', { email, password });
-  api.token = data.token;
-  await db.setMeta('token', data.token);
-  await db.setMeta('user', data.user);
-  try { localStorage.setItem('inknote_token', data.token); } catch {}
-  return data.user;
-}
-
-export async function register(email, password, displayName) {
-  const data = await api.post('/auth/register', { email, password, displayName });
-  api.token = data.token;
-  await db.setMeta('token', data.token);
-  await db.setMeta('user', data.user);
-  try { localStorage.setItem('inknote_token', data.token); } catch {}
-  return data.user;
-}
-
-export async function restoreSession() {
-  let token = await db.getMeta('token');
-  if (!token) { try { token = localStorage.getItem('inknote_token'); } catch {} }
-  if (!token) return null;
-  api.token = token;
-  if (_online) {
-    try { const u = await api.get('/auth/me'); await db.setMeta('user', u); return u; }
-    catch (e) { if (e.message === 'AUTH') { await logout(); return null; } }
-  }
-  return await db.getMeta('user') || {};
-}
-
-export async function logout() {
-  api.token = null;
-  try { localStorage.removeItem('inknote_token'); } catch {}
-  await db.clearAll();
-}
-
-/* ─── Account ─── */
-export async function updateProfile(displayName) {
-  const u = await api.put('/auth/profile', { displayName });
-  await db.setMeta('user', u);
-  return u;
-}
-export async function updateEmail(newEmail, password) {
-  const u = await api.put('/auth/email', { newEmail, password });
-  await db.setMeta('user', u);
-  return u;
-}
-export async function updatePassword(currentPassword, newPassword) {
-  await api.put('/auth/password', { currentPassword, newPassword });
-}
-
-/* ─── Full sync ─── */
-export async function fullSync() {
-  if (!_online || !api.token) return;
-  notifyStatus('syncing');
-  try {
-    await flushQueue();
-    const serverNbs = await api.get('/notebooks');
-    const nbs = serverNbs.map(nb => ({ id: nb.id, name: nb.name, cover: nb.cover_index || 0, sortOrder: nb.sort_order || 0 }));
-    await db.clearNotebooks();
-    if (nbs.length > 0) await db.putNotebooks(nbs);
-
-    const serverNotes = await api.get('/notes');
-    const active = serverNotes.map(n => ({ id: n.id, title: n.title, folderId: n.notebook_id, starred: !!n.starred, trashed: false, createdAt: n.created_at, updatedAt: n.updated_at }));
-    let trashed = [];
-    try {
-      const st = await api.get('/notes/trash');
-      trashed = st.map(n => ({ id: n.id, title: n.title, folderId: n.notebook_id, starred: !!n.starred, trashed: true, createdAt: n.created_at, updatedAt: n.updated_at || n.deleted_at }));
-    } catch {}
-
-    await db.clearNotes();
-    const all = [...active, ...trashed];
-    if (all.length > 0) await db.putNotes(all);
-    notifyStatus('synced');
-    notifyData('fullSync', null);
-  } catch (e) {
-    if (e.message === 'AUTH') throw e;
-    notifyStatus('error');
-  }
-}
-
-/* ─── Queue ─── */
-let _flushing = false;
-async function flushQueue() {
-  if (_flushing || !_online || !api.token) return;
-  _flushing = true;
-  try {
-    const pending = await db.peekQueue(100);
-    for (const entry of pending) {
-      try { await processEntry(entry); } catch (e) {
-        if (e.message === 'AUTH') { _flushing = false; throw e; }
-        if (!_online) break;
-        console.warn('[sync] skip failed entry:', entry.action, e.message);
-      }
-      await db.dequeue(entry.queueId);
-    }
-  } catch (e) { if (e.message === 'AUTH') throw e; }
-  _flushing = false;
-}
-
-async function processEntry(entry) {
-  const d = entry.data;
-  switch (entry.action) {
-    case 'createNotebook': {
-      const r = await api.post('/notebooks', { name: d.name, coverIndex: d.cover });
-      if (r.id !== d.localId) {
-        await db.deleteNotebook(d.localId);
-        await db.putNotebook({ id: r.id, name: d.name, cover: d.cover, sortOrder: d.sortOrder || 0 });
-        const notes = await db.getAllNotes();
-        for (const n of notes) { if (n.folderId === d.localId) { n.folderId = r.id; await db.putNote(n); } }
-      }
-      break;
-    }
-    case 'updateNotebook': await api.put(`/notebooks/${d.id}`, { name: d.name, coverIndex: d.cover, sortOrder: d.sortOrder }); break;
-    case 'deleteNotebook': await api.del(`/notebooks/${d.id}`); break;
-    case 'createNote': {
-      const content = await db.getNoteContent(d.localId);
-      const r = await api.post('/notes', { title: d.title, notebookId: d.folderId, content: content?.content || '' });
-      if (r.id !== d.localId) {
-        const old = await db.getNote(d.localId);
-        const oldC = await db.getNoteContent(d.localId);
-        await db.deleteNote(d.localId);
-        if (old) { delete old._pendingCreate; old.id = r.id; await db.putNote(old); }
-        if (oldC) await db.putNoteContent(r.id, oldC.content, oldC.drawingData);
-      }
-      break;
-    }
-    case 'updateNote': await api.put(`/notes/${d.id}`, d.updates); break;
-    case 'updateDrawing': await api.put(`/notes/${d.id}/drawing`, { drawingData: d.drawingData }); break;
-    case 'trashNote': await api.del(`/notes/${d.id}`); break;
-    case 'restoreNote': await api.put(`/notes/${d.id}/restore`, {}); break;
-    case 'permanentDelete': await api.del(`/notes/${d.id}/permanent`); break;
-    case 'emptyTrash': await api.del('/notes/trash/empty'); break;
-  }
-}
-
-/* ─── Debounce ─── */
-const _timers = {};
-function debounce(key, fn, ms = 800) { if (_timers[key]) clearTimeout(_timers[key]); _timers[key] = setTimeout(fn, ms); }
-
-/* ════════ PUBLIC DATA API ════════ */
-
-export async function getNotebooks() { return db.getAllNotebooks(); }
-
-export async function createNotebook({ name, cover }) {
-  if (_online && api.token) {
-    try {
-      const r = await api.post('/notebooks', { name, coverIndex: cover });
-      const nb = { id: r.id, name, cover, sortOrder: (await db.getAllNotebooks()).length };
-      await db.putNotebook(nb); notifyData('notebook', nb); return nb;
-    } catch (e) { if (e.message === 'AUTH') throw e; }
-  }
-  const lid = 'nb_' + Math.random().toString(36).slice(2, 10);
-  const nb = { id: lid, name, cover, sortOrder: (await db.getAllNotebooks()).length };
-  await db.putNotebook(nb);
-  await db.enqueue({ action: 'createNotebook', data: { localId: lid, name, cover, sortOrder: nb.sortOrder } });
-  notifyData('notebook', nb); notifyStatus('pending'); return nb;
-}
-
-export async function updateNotebook(id, updates) {
-  const nbs = await db.getAllNotebooks(); const nb = nbs.find(n => n.id === id); if (!nb) return;
-  const upd = { ...nb, ...updates }; await db.putNotebook(upd); notifyData('notebook', upd);
-  if (_online && api.token) { try { await api.put(`/notebooks/${id}`, { name: updates.name, coverIndex: updates.cover, sortOrder: updates.sortOrder }); return; } catch (e) { if (e.message === 'AUTH') throw e; } }
-  await db.enqueue({ action: 'updateNotebook', data: { id, name: updates.name, cover: updates.cover, sortOrder: updates.sortOrder } }); notifyStatus('pending');
-}
-
-export async function deleteNotebookLocal(id) {
-  const notes = await db.getAllNotes();
-  for (const n of notes) { if (n.folderId === id && !n.trashed) { n.trashed = true; await db.putNote(n); } }
-  await db.deleteNotebook(id); notifyData('notebook', { id, deleted: true });
-  if (_online && api.token) { try { await api.del(`/notebooks/${id}`); return; } catch (e) { if (e.message === 'AUTH') throw e; } }
-  await db.enqueue({ action: 'deleteNotebook', data: { id } }); notifyStatus('pending');
-}
-
-export async function reorderNotebooks(orderedIds) {
-  const nbs = await db.getAllNotebooks();
-  for (let i = 0; i < orderedIds.length; i++) { const nb = nbs.find(n => n.id === orderedIds[i]); if (nb) { nb.sortOrder = i; await db.putNotebook(nb); } }
-  notifyData('notebooks', null);
-  if (_online && api.token) { for (let i = 0; i < orderedIds.length; i++) { api.put(`/notebooks/${orderedIds[i]}`, { sortOrder: i }).catch(() => {}); } }
-}
-
-export async function getNotes() { return db.getAllNotes(); }
-
-export async function loadNoteContent(id, opts = {}) {
-  const forceRemote = !!opts.forceRemote;
-
-  // Local-first for instant editor open and resilience against slow/hung requests.
-  if (!forceRemote) {
-    const local = await db.getNoteContent(id);
-    if (local) {
-      if (_online && api.token) {
-        api.get(`/notes/${id}`).then(async (d) => {
-          const c = { content: d.content || '', drawingData: d.drawingData || null };
-          await db.putNoteContent(id, c.content, c.drawingData);
-        }).catch(() => {});
-      }
-      return { content: local.content || '', drawingData: local.drawingData || null };
-    }
-  }
-
-  // No local cache (or force remote): fetch server, then fallback to cache.
-  if (_online && api.token) {
-    try {
-      const d = await api.get(`/notes/${id}`);
-      const c = { content: d.content || '', drawingData: d.drawingData || null };
-      await db.putNoteContent(id, c.content, c.drawingData);
-      return c;
-    } catch {}
-  }
-  const local = await db.getNoteContent(id);
-  if (local) return { content: local.content || '', drawingData: local.drawingData || null };
-  return { content: '', drawingData: null };
-}
-
-export async function createNote(folderId) {
-  const ts = new Date().toISOString();
-  if (_online && api.token) {
-    try {
-      const r = await api.post('/notes', { title: 'Untitled Note', notebookId: folderId, content: '' });
-      const note = { id: r.id, title: 'Untitled Note', folderId, starred: false, trashed: false, createdAt: ts, updatedAt: ts };
-      await db.putNote(note); await db.putNoteContent(r.id, '', null); notifyData('note', note); return note;
-    } catch (e) { if (e.message === 'AUTH') throw e; }
-  }
-  const lid = 'local_' + Math.random().toString(36).slice(2, 10);
-  const note = { id: lid, title: 'Untitled Note', folderId, starred: false, trashed: false, createdAt: ts, updatedAt: ts, _pendingCreate: true };
-  await db.putNote(note); await db.putNoteContent(lid, '', null);
-  await db.enqueue({ action: 'createNote', data: { localId: lid, title: 'Untitled Note', folderId } });
-  notifyData('note', note); notifyStatus('pending'); return note;
-}
-
-export async function updateNoteTitle(id, title) {
-  const note = await db.getNote(id); if (!note) return;
-  note.title = title; note.updatedAt = new Date().toISOString(); await db.putNote(note); notifyData('note', note);
-  debounce(`title_${id}`, async () => {
-    if (_online && api.token && !note._pendingCreate) { try { await api.put(`/notes/${id}`, { title }); notifyStatus('synced'); return; } catch {} }
-    await db.enqueue({ action: 'updateNote', data: { id, updates: { title } } }); notifyStatus('pending');
-  });
-}
-
-export async function updateNoteContent(id, content) {
-  const ex = await db.getNoteContent(id); await db.putNoteContent(id, content, ex?.drawingData || null);
-  const note = await db.getNote(id); if (note) { note.updatedAt = new Date().toISOString(); await db.putNote(note); }
-  notifyData('noteContent', { id });
-  debounce(`content_${id}`, async () => {
-    if (_online && api.token && !note?._pendingCreate) { try { await api.put(`/notes/${id}`, { content }); notifyStatus('synced'); return; } catch {} }
-    await db.enqueue({ action: 'updateNote', data: { id, updates: { content } } }); notifyStatus('pending');
-  });
-}
-
-export async function updateNoteDrawing(id, drawingData) {
-  const ex = await db.getNoteContent(id); await db.putNoteContent(id, ex?.content || '', drawingData);
-  notifyData('noteContent', { id });
-  debounce(`drawing_${id}`, async () => {
-    const note = await db.getNote(id);
-    if (_online && api.token && !note?._pendingCreate) { try { await api.put(`/notes/${id}/drawing`, { drawingData }); notifyStatus('synced'); return; } catch {} }
-    await db.enqueue({ action: 'updateDrawing', data: { id, drawingData } }); notifyStatus('pending');
-  });
-}
-
-export async function toggleNoteStar(id) {
-  const note = await db.getNote(id); if (!note) return false;
-  note.starred = !note.starred; await db.putNote(note); notifyData('note', note);
-  if (_online && api.token && !note._pendingCreate) { api.put(`/notes/${id}`, { starred: note.starred }).catch(() => {}); }
-  else { await db.enqueue({ action: 'updateNote', data: { id, updates: { starred: note.starred } } }); notifyStatus('pending'); }
-  return note.starred;
-}
-
-export async function moveNote(id, fid) {
-  const note = await db.getNote(id); if (!note) return;
-  note.folderId = fid; note.updatedAt = new Date().toISOString(); await db.putNote(note); notifyData('note', note);
-  if (_online && api.token && !note._pendingCreate) { api.put(`/notes/${id}`, { notebookId: fid }).catch(() => {}); }
-  else { await db.enqueue({ action: 'updateNote', data: { id, updates: { notebookId: fid } } }); notifyStatus('pending'); }
-}
-
-export async function trashNote(id) {
-  const note = await db.getNote(id); if (!note) return;
-  note.trashed = true; note.updatedAt = new Date().toISOString(); await db.putNote(note); notifyData('note', note);
-  if (_online && api.token && !note._pendingCreate) { try { await api.del(`/notes/${id}`); } catch {} }
-  else { await db.enqueue({ action: 'trashNote', data: { id } }); notifyStatus('pending'); }
-}
-
-export async function restoreNoteLocal(id) {
-  const note = await db.getNote(id); if (!note) return;
-  note.trashed = false; note.updatedAt = new Date().toISOString(); await db.putNote(note); notifyData('note', note);
-  if (_online && api.token) { try { await api.put(`/notes/${id}/restore`, {}); } catch {} }
-  else { await db.enqueue({ action: 'restoreNote', data: { id } }); notifyStatus('pending'); }
-}
-
-export async function permanentDeleteNoteLocal(id) {
-  await db.deleteNote(id); notifyData('note', { id, deleted: true });
-  if (_online && api.token) { try { await api.del(`/notes/${id}/permanent`); } catch {} }
-  else { await db.enqueue({ action: 'permanentDelete', data: { id } }); notifyStatus('pending'); }
-}
-
-export async function emptyTrashLocal() {
-  const all = await db.getAllNotes(); for (const n of all) { if (n.trashed) await db.deleteNote(n.id); }
-  notifyData('notes', null);
-  if (_online && api.token) { try { await api.del('/notes/trash/empty'); } catch {} }
-  else { await db.enqueue({ action: 'emptyTrash', data: {} }); notifyStatus('pending'); }
-}
-
-export { DEVICE_ID };

frontend/src/syncEngine.test.ts

@@ -0,0 +1,393 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+
+import * as db from "./offlineStore";
+import * as sync from "./syncEngine";
+import type { NoteMeta, Notebook } from "./types";
+
+/* A stub transport. `req()` only ever touches status, ok and json(), so a plain
+ * object is enough and keeps the tests free of undici/jsdom differences. */
+type Reply = { status: number; body?: unknown };
+const reply = ({ status, body = {} }: Reply) => ({
+  status,
+  ok: status >= 200 && status < 300,
+  json: async () => body,
+});
+
+let calls: Array<{ method: string; url: string; body: unknown }> = [];
+let handler: (method: string, url: string, body: unknown) => Reply | Promise<Reply>;
+
+function installFetch() {
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async (url: string, opts: RequestInit = {}) => {
+      const method = opts.method || "GET";
+      const body = opts.body ? JSON.parse(opts.body as string) : undefined;
+      calls.push({ method, url, body });
+      return reply(await handler(method, url, body));
+    })
+  );
+}
+
+const succeed = () => {
+  handler = () => ({ status: 200, body: { id: "server-id" } });
+};
+const failWith = (status: number, body: unknown = { error: "nope" }) => {
+  handler = () => ({ status, body });
+};
+const failTransport = () => {
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async () => {
+      throw new TypeError("Failed to fetch");
+    })
+  );
+};
+
+const note = (id: string, over: Partial<NoteMeta> = {}): NoteMeta => ({
+  id,
+  title: `Note ${id}`,
+  folderId: "nb1",
+  starred: false,
+  trashed: false,
+  createdAt: "2026-01-01T00:00:00.000Z",
+  updatedAt: "2026-01-01T00:00:00.000Z",
+  ...over,
+});
+const notebook = (id: string, over: Partial<Notebook> = {}): Notebook => ({
+  id,
+  name: `NB ${id}`,
+  cover: 0,
+  sortOrder: 0,
+  ...over,
+});
+
+beforeEach(async () => {
+  await db.clearAll();
+  calls = [];
+  succeed();
+  installFetch();
+  sync.__testing.setToken("test-token");
+  sync.__testing.setOnline(true);
+  sync.__testing.resetPendingWrites();
+  vi.spyOn(console, "warn").mockImplementation(() => {});
+  vi.spyOn(console, "error").mockImplementation(() => {});
+  vi.spyOn(console, "info").mockImplementation(() => {});
+});
+
+afterEach(() => {
+  // Restored here as well as in each test: a timed-out test never runs its own
+  // cleanup, and leaked fake timers would hang every hook after it.
+  vi.useRealTimers();
+  vi.unstubAllGlobals();
+  vi.restoreAllMocks();
+});
+
+/** Fakes only setTimeout, so IndexedDB keeps working while the debounce does not. */
+const withFakeDebounce = async (fn: () => Promise<void>) => {
+  vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout"] });
+  try {
+    await fn();
+  } finally {
+    vi.useRealTimers();
+  }
+};
+
+describe("flushQueue", () => {
+  it("removes an entry once the server accepted it", async () => {
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+    await sync.__testing.flushQueue();
+    expect(await db.getQueueSize()).toBe(0);
+    expect(calls.map((c) => `${c.method} ${c.url}`)).toEqual(["DELETE /api/notes/n1"]);
+  });
+
+  it("keeps a failed entry queued and counts the attempt — losing it silently ate offline edits", async () => {
+    failWith(500);
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+    await sync.__testing.flushQueue();
+
+    const [entry] = await db.peekQueue();
+    expect(entry).toBeDefined();
+    expect(entry!.attempts).toBe(1);
+    expect(entry!.action).toBe("trashNote");
+  });
+
+  it("retries across flushes and gives up only after repeated failures", async () => {
+    failWith(500);
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+
+    for (let i = 1; i <= 4; i++) {
+      await sync.__testing.flushQueue();
+      const [entry] = await db.peekQueue();
+      expect(entry!.attempts).toBe(i);
+    }
+
+    // Fifth failure hits the cap; the entry is dropped so it cannot wedge the queue.
+    await sync.__testing.flushQueue();
+    expect(await db.getQueueSize()).toBe(0);
+  });
+
+  it("stops at the first transport failure and keeps everything for later", async () => {
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+    await db.enqueue({ action: "trashNote", data: { id: "n2" } });
+    failTransport();
+
+    await sync.__testing.flushQueue();
+
+    expect(await db.getQueueSize()).toBe(2);
+    const entries = await db.peekQueue();
+    // Nothing is counted as a failed attempt: being offline is not the entry's fault.
+    expect(entries.every((e) => e.attempts === undefined)).toBe(true);
+  });
+
+  it("propagates an auth failure and leaves the queue untouched", async () => {
+    failWith(401);
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+
+    await expect(sync.__testing.flushQueue()).rejects.toThrow("AUTH");
+    expect(await db.getQueueSize()).toBe(1);
+  });
+
+  it("processes entries in the order they were queued", async () => {
+    await db.enqueue({ action: "trashNote", data: { id: "first" } });
+    await db.enqueue({ action: "trashNote", data: { id: "second" } });
+    await sync.__testing.flushQueue();
+    expect(calls.map((c) => c.url)).toEqual(["/api/notes/first", "/api/notes/second"]);
+  });
+
+  it("does nothing while signed out", async () => {
+    sync.__testing.setToken(null);
+    await db.enqueue({ action: "trashNote", data: { id: "n1" } });
+    await sync.__testing.flushQueue();
+    expect(calls.length).toBe(0);
+    expect(await db.getQueueSize()).toBe(1);
+  });
+
+  it("repoints notes at the server id when a queued notebook is finally created", async () => {
+    await db.putNotebook(notebook("nb_local", { _pendingCreate: true }));
+    await db.putNote(note("n1", { folderId: "nb_local" }));
+    await db.enqueue({
+      action: "createNotebook",
+      data: { localId: "nb_local", name: "Later", cover: 0, sortOrder: 0 },
+    });
+
+    await sync.__testing.flushQueue();
+
+    expect((await db.getNote("n1"))?.folderId).toBe("server-id");
+    expect((await db.getAllNotebooks()).map((n) => n.id)).toEqual(["server-id"]);
+  });
+});
+
+describe("fullSync", () => {
+  const serverState = (notes: unknown[], notebooks: unknown[]) => {
+    handler = (_method, url) => {
+      if (url.endsWith("/notebooks")) return { status: 200, body: notebooks };
+      if (url.endsWith("/notes/trash")) return { status: 200, body: [] };
+      if (url.endsWith("/notes")) return { status: 200, body: notes };
+      return { status: 200, body: {} };
+    };
+  };
+
+  it("mirrors the server's notes and notebooks", async () => {
+    serverState(
+      [{ id: "s1", title: "Server note", notebook_id: "snb", created_at: "t", updated_at: "t" }],
+      [{ id: "snb", name: "Server book", cover_index: 2, sort_order: 1 }]
+    );
+    await sync.fullSync();
+
+    expect((await db.getAllNotes()).map((n) => n.id)).toEqual(["s1"]);
+    const [nb] = await db.getAllNotebooks();
+    expect(nb).toMatchObject({ id: "snb", name: "Server book", cover: 2, sortOrder: 1 });
+  });
+
+  it("keeps notes created offline that the server has never seen", async () => {
+    await db.putNote(note("local_1", { _pendingCreate: true }));
+    await db.putNote(note("stale_1")); // synced earlier, since deleted elsewhere
+    serverState([], []);
+
+    await sync.fullSync();
+
+    const ids = (await db.getAllNotes()).map((n) => n.id);
+    expect(ids).toContain("local_1");
+    expect(ids).not.toContain("stale_1");
+  });
+
+  it("keeps notebooks created offline", async () => {
+    await db.putNotebook(notebook("nb_local", { _pendingCreate: true }));
+    serverState([], []);
+
+    await sync.fullSync();
+
+    expect((await db.getAllNotebooks()).map((n) => n.id)).toContain("nb_local");
+  });
+
+  it("drops the local-only flag once the server reports the same id", async () => {
+    await db.putNote(note("s1", { _pendingCreate: true }));
+    serverState(
+      [{ id: "s1", title: "Now on server", notebook_id: null, created_at: "t", updated_at: "t" }],
+      []
+    );
+
+    await sync.fullSync();
+
+    const [n] = await db.getAllNotes();
+    expect(n!._pendingCreate).toBeUndefined();
+    expect(n!.title).toBe("Now on server");
+  });
+
+  it("leaves the local mirror intact when a server read fails midway", async () => {
+    await db.putNote(note("keep"));
+    await db.putNotebook(notebook("keep_nb"));
+    handler = (_method, url) => {
+      if (url.endsWith("/notebooks")) return { status: 200, body: [] };
+      return { status: 500, body: { error: "boom" } }; // the notes read fails
+    };
+
+    await sync.fullSync();
+
+    expect((await db.getAllNotes()).map((n) => n.id)).toEqual(["keep"]);
+    expect((await db.getAllNotebooks()).map((n) => n.id)).toEqual(["keep_nb"]);
+  });
+
+  it("does nothing while signed out", async () => {
+    sync.__testing.setToken(null);
+    await sync.fullSync();
+    expect(calls.length).toBe(0);
+  });
+});
+
+describe("hasPendingWrites", () => {
+  it("is false without an id", () => {
+    expect(sync.hasPendingWrites(null)).toBe(false);
+    expect(sync.hasPendingWrites(undefined)).toBe(false);
+    expect(sync.hasPendingWrites("")).toBe(false);
+  });
+
+  it("is false for a note nobody is writing", () => {
+    expect(sync.hasPendingWrites("n1")).toBe(false);
+  });
+
+  it("reports a write that is in flight — the guard that stops stale reads winning", () => {
+    sync.__testing.beginWrite("n1");
+    expect(sync.hasPendingWrites("n1")).toBe(true);
+    expect(sync.hasPendingWrites("n2")).toBe(false);
+    sync.__testing.endWrite("n1");
+    expect(sync.hasPendingWrites("n1")).toBe(false);
+  });
+
+  it("stays true until the last of several overlapping writes finishes", () => {
+    sync.__testing.beginWrite("n1");
+    sync.__testing.beginWrite("n1");
+    sync.__testing.endWrite("n1");
+    expect(sync.hasPendingWrites("n1")).toBe(true);
+    sync.__testing.endWrite("n1");
+    expect(sync.hasPendingWrites("n1")).toBe(false);
+  });
+
+  it("covers the debounce window before a save even starts", async () => {
+    await db.putNote(note("n1"));
+    await withFakeDebounce(async () => {
+      await sync.updateNoteContent("n1", "typing…");
+      // The request has not been sent yet, but the note must already count as busy.
+      expect(sync.hasPendingWrites("n1")).toBe(true);
+      await vi.runAllTimersAsync();
+    });
+    expect(sync.hasPendingWrites("n1")).toBe(false);
+  });
+});
+
+describe("updateNoteContent", () => {
+  it("writes locally before anything reaches the network", async () => {
+    await db.putNote(note("n1"));
+    await sync.updateNoteContent("n1", "body text");
+    expect((await db.getNoteContent("n1"))?.content).toBe("body text");
+    expect(calls.length).toBe(0); // still inside the debounce window
+  });
+
+  it("sends links along with the body, since the server cannot read it", async () => {
+    await db.putNote(note("n1"));
+    await withFakeDebounce(async () => {
+      await sync.updateNoteContent("n1", "body", ["target-1"]);
+      await vi.runAllTimersAsync();
+    });
+    const put = calls.find((c) => c.method === "PUT");
+    expect(put?.body).toMatchObject({ content: "body", links: ["target-1"] });
+  });
+
+  it("omits the links field when the caller passes none", async () => {
+    await db.putNote(note("n1"));
+    await withFakeDebounce(async () => {
+      await sync.updateNoteContent("n1", "body");
+      await vi.runAllTimersAsync();
+    });
+    const put = calls.find((c) => c.method === "PUT");
+    expect(put?.body).toEqual({ content: "body" });
+  });
+
+  it("queues the change when the request fails", async () => {
+    failWith(500);
+    await db.putNote(note("n1"));
+    await withFakeDebounce(async () => {
+      await sync.updateNoteContent("n1", "body");
+      await vi.runAllTimersAsync();
+    });
+    const [entry] = await db.peekQueue();
+    expect(entry?.action).toBe("updateNote");
+  });
+});
+
+describe("loadNoteContent", () => {
+  it("returns the cached body without waiting for the server", async () => {
+    await db.putNoteContent("n1", "cached", null);
+    const c = await sync.loadNoteContent("n1");
+    expect(c.content).toBe("cached");
+  });
+
+  it("does not refresh from the server while a write is in flight", async () => {
+    await db.putNoteContent("n1", "cached", null);
+    sync.__testing.beginWrite("n1");
+    await sync.loadNoteContent("n1");
+    expect(calls.length).toBe(0);
+    sync.__testing.endWrite("n1");
+  });
+
+  it("falls back to the cache when the server read fails", async () => {
+    await db.putNoteContent("n1", "cached", null);
+    failWith(500);
+    const c = await sync.loadNoteContent("n1", { forceRemote: true });
+    expect(c.content).toBe("cached");
+  });
+
+  it("returns an empty shape for a note with nothing cached and no connection", async () => {
+    sync.__testing.setOnline(false);
+    const c = await sync.loadNoteContent("missing");
+    expect(c).toEqual({ content: "", drawingData: null, drawingStrokes: null, updatedAt: null });
+    sync.__testing.setOnline(true);
+  });
+});
+
+describe("offline behaviour", () => {
+  beforeEach(() => sync.__testing.setOnline(false));
+  afterEach(() => sync.__testing.setOnline(true));
+
+  it("creates a note locally and queues it", async () => {
+    const n = await sync.createNote("nb1");
+    expect(n._pendingCreate).toBe(true);
+    expect(calls.length).toBe(0);
+    const [entry] = await db.peekQueue();
+    expect(entry?.action).toBe("createNote");
+  });
+
+  it("creates a notebook locally, flagged so fullSync will not drop it", async () => {
+    const nb = await sync.createNotebook({ name: "Later", cover: 1 });
+    expect(nb._pendingCreate).toBe(true);
+    expect((await db.getAllNotebooks())[0]?._pendingCreate).toBe(true);
+  });
+
+  it("queues a star toggle instead of losing it", async () => {
+    await db.putNote(note("n1"));
+    expect(await sync.toggleNoteStar("n1")).toBe(true);
+    const [entry] = await db.peekQueue();
+    expect(entry?.action).toBe("updateNote");
+    expect((await db.getNote("n1"))?.starred).toBe(true);
+  });
+});

frontend/src/test/setup.js

@@ -0,0 +1,3 @@
+// IndexedDB is not part of jsdom; this gives the store layer a real one to
+// exercise, so the tests cover actual transactions rather than a hand-rolled mock.
+import "fake-indexeddb/auto";

frontend/src/types.ts

@@ -0,0 +1,147 @@
+/**
+ * The shapes that travel between the server, IndexedDB and the UI.
+ *
+ * Most bugs in this app have been shape bugs: a field that is sometimes absent,
+ * a body cached in the wrong format, a stale object adopted over a fresh one.
+ * These types exist to make that class of mistake fail at build time.
+ */
+
+/* ── Drawing ── */
+
+export type StrokeTool = "pen" | "highlighter" | "eraser";
+
+export interface Stroke {
+  /** Tool the stroke was drawn with. */
+  t: StrokeTool;
+  /** Colour, `#rrggbb`. */
+  c: string;
+  /** Width in canonical page units, not pixels. */
+  s: number;
+  /** Flat `[x0, y0, x1, y1, …]` in canonical page space. */
+  p: number[];
+}
+
+export interface StrokeDoc {
+  v: number;
+  /** Canonical page width the points are expressed in. */
+  w: number;
+  /** Canonical page height. */
+  h: number;
+  strokes: Stroke[];
+  /** Save token — lets the editor recognise its own write coming back. */
+  t?: string;
+}
+
+/* ── Notes ── */
+
+/** Note metadata, as held in the notes list. */
+export interface NoteMeta {
+  id: string;
+  title: string;
+  folderId: string | null;
+  starred: boolean;
+  trashed: boolean;
+  createdAt: string;
+  updatedAt: string;
+  /** Set while a note created offline has not reached the server yet. */
+  _pendingCreate?: boolean;
+}
+
+/** The lazily loaded body of a note. */
+export interface NoteContent {
+  /** Serialised document: `{"v":2,"doc":…}`, or a v1 `{html,tasks}` string. */
+  content: string;
+  /** Legacy raster drawing as a data URL, for notes predating vector strokes. */
+  drawingData: string | null;
+  drawingStrokes: StrokeDoc | null;
+  /** Server revision this copy came from, used to spot a stale cache. */
+  updatedAt?: string | null;
+}
+
+export interface Notebook {
+  id: string;
+  name: string;
+  cover: number;
+  sortOrder: number;
+  _pendingCreate?: boolean;
+}
+
+export interface User {
+  id: string;
+  username: string;
+  displayName: string;
+}
+
+/* ── Version history ── */
+
+export type VersionReason = "edit" | "large-deletion" | "drawing" | "drawing-cleared" | "before-restore";
+
+export interface NoteVersionSummary {
+  id: number;
+  title: string | null;
+  device_id: string | null;
+  reason: VersionReason | string;
+  created_at: string;
+  content_size: number | null;
+  has_drawing: boolean;
+}
+
+export interface NoteVersion {
+  id: number;
+  title: string | null;
+  created_at: string;
+  device_id: string | null;
+  reason: string;
+  content: string;
+  drawingStrokes: StrokeDoc | null;
+}
+
+/* ── Links ── */
+
+export interface Backlink {
+  id: string;
+  title: string;
+  notebook_id: string | null;
+  notebook_name: string | null;
+  updated_at: string;
+}
+
+export type LinkKind = "note" | "notebook";
+
+export interface LinkTarget {
+  id: string;
+  label: string;
+  kind: LinkKind;
+}
+
+/* ── Sync ── */
+
+export type SyncStatus = "synced" | "syncing" | "pending" | "offline" | "error";
+
+/** A change waiting to be pushed to the server. */
+export interface QueueEntry {
+  queueId: number;
+  action: string;
+  data: Record<string, unknown>;
+  timestamp: number;
+  attempts?: number;
+  lastError?: string;
+}
+
+/* ── Attachments ── */
+
+export interface AttachmentInfo {
+  id: string;
+  mime: string;
+  size: number;
+  deduplicated: boolean;
+}
+
+/* ── Search ── */
+
+export interface SearchHit {
+  id: string;
+  score: number;
+  /** Excerpt around the first matching term. */
+  snippet: string;
+}

frontend/src/ui/AccountMenu.jsx

@@ -0,0 +1,394 @@
+import { useMemo, useState } from "react";
+import * as sync from "../syncEngine";
+import { I } from "./icons.jsx";
+
+/* ═══════ ACCOUNT MENU ═══════ */
+export function AccountMenu({ user, onClose, onLogout, onUserUpdate, dark }) {
+  const [tab, setTab] = useState("profile"); // profile | username | password
+  const [displayName, setDisplayName] = useState(user?.displayName || "");
+  const [newUsername, setNewUsername] = useState(user?.username || "");
+  const [usernamePass, setUsernamePass] = useState("");
+  const [curPass, setCurPass] = useState("");
+  const [newPass, setNewPass] = useState("");
+  const [newPass2, setNewPass2] = useState("");
+  const [msg, setMsg] = useState("");
+  const [err, setErr] = useState("");
+  const [saving, setSaving] = useState(false);
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      accent: dark ? "#388bfd" : "#0969da",
+      danger: dark ? "#f85149" : "#cf222e",
+      success: dark ? "#3fb950" : "#1a7f37",
+      inputBg: dark ? "#0d1117" : "#f6f8fa",
+    }),
+    [dark]
+  );
+  const inp = {
+    width: "100%",
+    padding: "10px 14px",
+    borderRadius: 10,
+    border: `1px solid ${T.border}`,
+    background: T.inputBg,
+    color: T.text,
+    fontSize: 14,
+    outline: "none",
+    boxSizing: "border-box",
+    marginBottom: 10,
+    fontFamily: "'DM Sans',sans-serif",
+  };
+  const tbtn = (active) => ({
+    padding: "7px 14px",
+    borderRadius: 8,
+    border: "none",
+    cursor: "pointer",
+    fontSize: 12,
+    fontWeight: 600,
+    background: active ? T.accent + "22" : "transparent",
+    color: active ? T.accent : T.muted,
+  });
+  const clear = () => {
+    setMsg("");
+    setErr("");
+  };
+
+  const saveProfile = async () => {
+    if (!displayName.trim()) return;
+    clear();
+    setSaving(true);
+    try {
+      const u = await sync.updateProfile(displayName.trim());
+      onUserUpdate(u);
+      setMsg("Display name updated");
+    } catch (e) {
+      setErr(e.message);
+    }
+    setSaving(false);
+  };
+  const saveUsername = async () => {
+    if (!newUsername || !usernamePass) return;
+    clear();
+    setSaving(true);
+    try {
+      const u = await sync.updateUsername(newUsername.trim(), usernamePass);
+      onUserUpdate(u);
+      setUsernamePass("");
+      setMsg("Username updated");
+    } catch (e) {
+      setErr(e.message);
+    }
+    setSaving(false);
+  };
+  const savePassword = async () => {
+    if (!curPass || !newPass) return;
+    if (newPass !== newPass2) {
+      setErr("Passwords don't match");
+      return;
+    }
+    clear();
+    setSaving(true);
+    try {
+      await sync.updatePassword(curPass, newPass);
+      setCurPass("");
+      setNewPass("");
+      setNewPass2("");
+      setMsg("Password changed");
+    } catch (e) {
+      setErr(e.message);
+    }
+    setSaving(false);
+  };
+
+  return (
+    <div
+      style={{
+        position: "fixed",
+        inset: 0,
+        background: "rgba(0,0,0,0.55)",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        zIndex: 2000,
+        backdropFilter: "blur(6px)",
+      }}
+      onClick={onClose}
+    >
+      <div
+        style={{
+          background: T.bg,
+          borderRadius: 20,
+          padding: 0,
+          width: 440,
+          maxWidth: "92vw",
+          boxShadow: "0 24px 48px rgba(0,0,0,0.3)",
+          border: `1px solid ${T.border}`,
+          overflow: "hidden",
+        }}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <div
+          style={{
+            display: "flex",
+            alignItems: "center",
+            justifyContent: "space-between",
+            padding: "18px 22px",
+            borderBottom: `1px solid ${T.border}`,
+          }}
+        >
+          <h3
+            style={{
+              margin: 0,
+              fontSize: 17,
+              fontWeight: 600,
+              color: T.text,
+              fontFamily: "'Newsreader',Georgia,serif",
+            }}
+          >
+            Account
+          </h3>
+          <button
+            onClick={onClose}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+              width: 28,
+              height: 28,
+              borderRadius: 8,
+              border: "none",
+              background: "transparent",
+              cursor: "pointer",
+              color: T.muted,
+            }}
+          >
+            {I.x}
+          </button>
+        </div>
+        <div
+          style={{ display: "flex", gap: 4, padding: "12px 22px 0", borderBottom: `1px solid ${T.border}` }}
+        >
+          <button
+            onClick={() => {
+              setTab("profile");
+              clear();
+            }}
+            style={tbtn(tab === "profile")}
+          >
+            Profile
+          </button>
+          <button
+            onClick={() => {
+              setTab("username");
+              clear();
+            }}
+            style={tbtn(tab === "username")}
+          >
+            Username
+          </button>
+          <button
+            onClick={() => {
+              setTab("password");
+              clear();
+            }}
+            style={tbtn(tab === "password")}
+          >
+            Password
+          </button>
+        </div>
+        <div style={{ padding: "18px 22px 22px" }}>
+          {msg && (
+            <div
+              style={{
+                color: T.success,
+                fontSize: 12,
+                marginBottom: 10,
+                padding: "8px 12px",
+                borderRadius: 8,
+                background: T.success + "15",
+              }}
+            >
+              {msg}
+            </div>
+          )}
+          {err && (
+            <div
+              style={{
+                color: T.danger,
+                fontSize: 12,
+                marginBottom: 10,
+                padding: "8px 12px",
+                borderRadius: 8,
+                background: T.danger + "12",
+              }}
+            >
+              {err}
+            </div>
+          )}
+
+          {tab === "profile" && (
+            <>
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                Display Name
+              </label>
+              <input
+                type="text"
+                value={displayName}
+                onChange={(e) => setDisplayName(e.target.value)}
+                style={inp}
+                onKeyDown={(e) => {
+                  if (e.key === "Enter") saveProfile();
+                }}
+              />
+              <button
+                onClick={saveProfile}
+                disabled={saving}
+                style={{
+                  width: "100%",
+                  padding: "10px",
+                  borderRadius: 10,
+                  border: "none",
+                  background: T.accent,
+                  color: "#fff",
+                  cursor: "pointer",
+                  fontSize: 13,
+                  fontWeight: 600,
+                  opacity: saving ? 0.6 : 1,
+                }}
+              >
+                {saving ? "Saving..." : "Save Changes"}
+              </button>
+            </>
+          )}
+
+          {tab === "username" && (
+            <>
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                New Username
+              </label>
+              <input
+                type="text"
+                value={newUsername}
+                onChange={(e) => setNewUsername(e.target.value)}
+                autoCapitalize="none"
+                autoCorrect="off"
+                spellCheck={false}
+                style={inp}
+              />
+              <div style={{ fontSize: 11, color: T.muted, marginTop: -6, marginBottom: 10 }}>
+                3–32 characters · letters, digits, . _ -
+              </div>
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                Confirm Password
+              </label>
+              <input
+                type="password"
+                value={usernamePass}
+                onChange={(e) => setUsernamePass(e.target.value)}
+                style={inp}
+                onKeyDown={(e) => {
+                  if (e.key === "Enter") saveUsername();
+                }}
+              />
+              <button
+                onClick={saveUsername}
+                disabled={saving}
+                style={{
+                  width: "100%",
+                  padding: "10px",
+                  borderRadius: 10,
+                  border: "none",
+                  background: T.accent,
+                  color: "#fff",
+                  cursor: "pointer",
+                  fontSize: 13,
+                  fontWeight: 600,
+                  opacity: saving ? 0.6 : 1,
+                }}
+              >
+                {saving ? "Saving..." : "Update Username"}
+              </button>
+            </>
+          )}
+
+          {tab === "password" && (
+            <>
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                Current Password
+              </label>
+              <input
+                type="password"
+                value={curPass}
+                onChange={(e) => setCurPass(e.target.value)}
+                style={inp}
+              />
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                New Password
+              </label>
+              <input
+                type="password"
+                value={newPass}
+                onChange={(e) => setNewPass(e.target.value)}
+                style={inp}
+              />
+              <label style={{ fontSize: 12, color: T.muted, marginBottom: 4, display: "block" }}>
+                Confirm New Password
+              </label>
+              <input
+                type="password"
+                value={newPass2}
+                onChange={(e) => setNewPass2(e.target.value)}
+                style={inp}
+                onKeyDown={(e) => {
+                  if (e.key === "Enter") savePassword();
+                }}
+              />
+              <button
+                onClick={savePassword}
+                disabled={saving}
+                style={{
+                  width: "100%",
+                  padding: "10px",
+                  borderRadius: 10,
+                  border: "none",
+                  background: T.accent,
+                  color: "#fff",
+                  cursor: "pointer",
+                  fontSize: 13,
+                  fontWeight: 600,
+                  opacity: saving ? 0.6 : 1,
+                }}
+              >
+                {saving ? "Saving..." : "Change Password"}
+              </button>
+            </>
+          )}
+        </div>
+        <div style={{ padding: "0 22px 18px" }}>
+          <button
+            onClick={onLogout}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              gap: 8,
+              width: "100%",
+              padding: "10px",
+              borderRadius: 10,
+              border: `1px solid ${T.danger}33`,
+              background: T.danger + "08",
+              cursor: "pointer",
+              color: T.danger,
+              fontSize: 13,
+              fontWeight: 600,
+              justifyContent: "center",
+            }}
+          >
+            {I.logout} Sign Out
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/ui/AuthScreen.jsx

@@ -0,0 +1,222 @@
+import { useMemo, useState } from "react";
+import * as sync from "../syncEngine";
+
+/* ═══════ AUTH SCREEN ═══════ */
+export function AuthScreen({ onLogin, dark }) {
+  const [isLogin, setIsLogin] = useState(true);
+  const [username, setUsername] = useState("");
+  const [pass, setPass] = useState("");
+  const [name, setName] = useState("");
+  const [err, setErr] = useState("");
+  const [loading, setLoading] = useState(false);
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#0d1117" : "#f6f8fa",
+      card: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      accent: dark ? "#388bfd" : "#0969da",
+      danger: dark ? "#f85149" : "#cf222e",
+    }),
+    [dark]
+  );
+  const submit = async () => {
+    const u = username.trim();
+    if (!u || !pass) {
+      setErr("Username and password required");
+      return;
+    }
+    if (!isLogin && !/^[a-zA-Z0-9._-]{3,32}$/.test(u)) {
+      setErr("Username must be 3-32 chars: letters, digits, . _ -");
+      return;
+    }
+    setLoading(true);
+    setErr("");
+    try {
+      const user = isLogin ? await sync.login(u, pass) : await sync.register(u, pass, name || undefined);
+      onLogin(user);
+    } catch (e) {
+      setErr(e.message === "AUTH" ? "Invalid credentials" : e.message);
+    } finally {
+      setLoading(false);
+    }
+  };
+  return (
+    <div
+      style={{
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        minHeight: "100vh",
+        background: T.bg,
+        fontFamily: "'DM Sans',sans-serif",
+      }}
+    >
+      <div
+        style={{
+          background: T.card,
+          borderRadius: 24,
+          padding: 40,
+          width: 400,
+          maxWidth: "90vw",
+          boxShadow: "0 20px 60px rgba(0,0,0,0.15)",
+          border: `1px solid ${T.border}`,
+        }}
+      >
+        <div style={{ display: "flex", alignItems: "center", gap: 12, marginBottom: 28 }}>
+          <div
+            style={{
+              width: 42,
+              height: 42,
+              borderRadius: 14,
+              background: `linear-gradient(135deg,${T.accent},#a855f7)`,
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+              fontSize: 22,
+            }}
+          >
+            ✏️
+          </div>
+          <div>
+            <div
+              style={{
+                fontSize: 22,
+                fontWeight: 700,
+                color: T.text,
+                fontFamily: "'Newsreader',Georgia,serif",
+              }}
+            >
+              InkNote
+            </div>
+            <div style={{ fontSize: 12, color: T.muted }}>
+              {isLogin ? "Sign in to sync your notes" : "Create your account"}
+            </div>
+          </div>
+        </div>
+        {!isLogin && (
+          <input
+            type="text"
+            value={name}
+            onChange={(e) => setName(e.target.value)}
+            placeholder="Display name"
+            style={{
+              width: "100%",
+              padding: "12px 16px",
+              borderRadius: 12,
+              border: `1px solid ${T.border}`,
+              background: T.bg,
+              color: T.text,
+              fontSize: 14,
+              outline: "none",
+              marginBottom: 12,
+              boxSizing: "border-box",
+            }}
+          />
+        )}
+        <input
+          type="text"
+          value={username}
+          onChange={(e) => setUsername(e.target.value)}
+          placeholder="Username"
+          autoFocus
+          autoCapitalize="none"
+          autoCorrect="off"
+          spellCheck={false}
+          autoComplete="username"
+          style={{
+            width: "100%",
+            padding: "12px 16px",
+            borderRadius: 12,
+            border: `1px solid ${T.border}`,
+            background: T.bg,
+            color: T.text,
+            fontSize: 14,
+            outline: "none",
+            marginBottom: 12,
+            boxSizing: "border-box",
+          }}
+          onKeyDown={(e) => {
+            if (e.key === "Enter") submit();
+          }}
+        />
+        <input
+          type="password"
+          value={pass}
+          onChange={(e) => setPass(e.target.value)}
+          placeholder="Password"
+          autoComplete={isLogin ? "current-password" : "new-password"}
+          style={{
+            width: "100%",
+            padding: "12px 16px",
+            borderRadius: 12,
+            border: `1px solid ${T.border}`,
+            background: T.bg,
+            color: T.text,
+            fontSize: 14,
+            outline: "none",
+            marginBottom: 16,
+            boxSizing: "border-box",
+          }}
+          onKeyDown={(e) => {
+            if (e.key === "Enter") submit();
+          }}
+        />
+        {err && (
+          <div
+            style={{
+              color: T.danger,
+              fontSize: 12,
+              marginBottom: 12,
+              padding: "8px 12px",
+              borderRadius: 8,
+              background: T.danger + "12",
+            }}
+          >
+            {err}
+          </div>
+        )}
+        <button
+          onClick={submit}
+          disabled={loading}
+          style={{
+            width: "100%",
+            padding: "12px",
+            borderRadius: 12,
+            border: "none",
+            background: T.accent,
+            color: "#fff",
+            cursor: "pointer",
+            fontSize: 14,
+            fontWeight: 600,
+            marginBottom: 16,
+            opacity: loading ? 0.6 : 1,
+          }}
+        >
+          {loading ? "..." : isLogin ? "Sign In" : "Create Account"}
+        </button>
+        <div style={{ textAlign: "center", fontSize: 13, color: T.muted }}>
+          {isLogin ? "Don't have an account? " : "Already have an account? "}
+          <button
+            onClick={() => {
+              setIsLogin(!isLogin);
+              setErr("");
+            }}
+            style={{
+              background: "none",
+              border: "none",
+              color: T.accent,
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 600,
+              textDecoration: "underline",
+            }}
+          >
+            {isLogin ? "Sign Up" : "Sign In"}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/ui/BackButton.jsx

@@ -0,0 +1,26 @@
+import { I } from "./icons.jsx";
+
+/** Phone-only return arrow; desktop keeps list and editor side by side. */
+export function BackButton({ T, label = "Back", onClick }) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        display: "flex",
+        alignItems: "center",
+        gap: 6,
+        padding: "6px 10px",
+        borderRadius: 8,
+        border: "none",
+        background: "transparent",
+        cursor: "pointer",
+        color: T.accent,
+        fontSize: 13,
+        fontWeight: 600,
+      }}
+    >
+      {I.back}
+      {label}
+    </button>
+  );
+}

frontend/src/ui/BacklinksPanel.jsx

@@ -0,0 +1,110 @@
+import { useMemo, useState } from "react";
+
+/* ═══════ BACKLINKS ═══════ */
+/* Notes that point at the one currently open. The reverse direction is not part
+ * of the note itself, so it can only come from the server's link index.
+ *
+ * Sits as a bar under the editor rather than after the page: a page is a fixed
+ * 4:3 sheet, so anything placed below it starts a full screen out of sight. */
+export function BacklinksPanel({ backlinks, onOpenNote, dark }) {
+  const [open, setOpen] = useState(false);
+  if (!backlinks || backlinks.length === 0) return null;
+  const T = {
+    border: dark ? "#30363d" : "#d0d7de",
+    muted: dark ? "#8b949e" : "#656d76",
+    surface: dark ? "#161b22" : "#f6f8fa",
+    accent: dark ? "#388bfd" : "#0969da",
+  };
+  return (
+    <div
+      style={{
+        borderTop: `1px solid ${T.border}`,
+        background: T.surface,
+        flexShrink: 0,
+        maxHeight: "38vh",
+        display: "flex",
+        flexDirection: "column",
+      }}
+    >
+      <button
+        onClick={() => setOpen((o) => !o)}
+        style={{
+          display: "flex",
+          alignItems: "center",
+          gap: 8,
+          width: "100%",
+          padding: "9px 16px",
+          border: "none",
+          background: "transparent",
+          cursor: "pointer",
+          color: T.muted,
+          fontSize: 11,
+          fontWeight: 700,
+          letterSpacing: 0.6,
+          textTransform: "uppercase",
+          textAlign: "left",
+          flexShrink: 0,
+        }}
+      >
+        <span
+          style={{
+            display: "inline-block",
+            transform: open ? "rotate(90deg)" : "none",
+            transition: "transform .15s",
+          }}
+        >
+          ▸
+        </span>
+        <span>
+          Linked from {backlinks.length} {backlinks.length === 1 ? "note" : "notes"}
+        </span>
+      </button>
+      {open && (
+        <div
+          style={{
+            display: "flex",
+            flexDirection: "column",
+            gap: 2,
+            padding: "0 10px 10px",
+            overflowY: "auto",
+          }}
+        >
+          {backlinks.map((b) => (
+            <button
+              key={b.id}
+              onClick={() => onOpenNote?.(b.id)}
+              style={{
+                display: "flex",
+                alignItems: "baseline",
+                gap: 8,
+                width: "100%",
+                padding: "7px 9px",
+                border: "none",
+                borderRadius: 8,
+                background: "transparent",
+                cursor: "pointer",
+                textAlign: "left",
+              }}
+            >
+              <span
+                style={{
+                  fontSize: 13,
+                  color: T.accent,
+                  fontWeight: 600,
+                  overflow: "hidden",
+                  textOverflow: "ellipsis",
+                  whiteSpace: "nowrap",
+                }}
+              >
+                {b.title || "Untitled"}
+              </span>
+              {b.notebook_name && (
+                <span style={{ fontSize: 11, color: T.muted, flexShrink: 0 }}>in {b.notebook_name}</span>
+              )}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/ui/ConfirmDialog.jsx

@@ -0,0 +1,98 @@
+import { useMemo } from "react";
+
+/* ═══════ Shared Components ═══════ */
+export function ConfirmDialog({ title, message, confirmLabel = "Delete", onConfirm, onCancel, dark }) {
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      danger: dark ? "#f85149" : "#cf222e",
+    }),
+    [dark]
+  );
+  return (
+    <div
+      style={{
+        position: "fixed",
+        inset: 0,
+        background: "rgba(0,0,0,0.5)",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        zIndex: 2000,
+        backdropFilter: "blur(4px)",
+      }}
+      onClick={onCancel}
+    >
+      <div
+        style={{
+          background: T.bg,
+          borderRadius: 16,
+          padding: 26,
+          width: 380,
+          maxWidth: "90vw",
+          boxShadow: "0 20px 40px rgba(0,0,0,0.3)",
+          border: `1px solid ${T.border}`,
+        }}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <div
+          style={{
+            fontSize: 17,
+            fontWeight: 600,
+            color: T.text,
+            marginBottom: 8,
+            fontFamily: "'Newsreader',Georgia,serif",
+          }}
+        >
+          {title}
+        </div>
+        <div
+          style={{
+            fontSize: 13,
+            color: T.muted,
+            lineHeight: 1.6,
+            marginBottom: 22,
+            fontFamily: "'DM Sans',sans-serif",
+          }}
+        >
+          {message}
+        </div>
+        <div style={{ display: "flex", gap: 10, justifyContent: "flex-end" }}>
+          <button
+            onClick={onCancel}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: `1px solid ${T.border}`,
+              background: "transparent",
+              color: T.text,
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Cancel
+          </button>
+          <button
+            onClick={onConfirm}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: "none",
+              background: T.danger,
+              color: "#fff",
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            {confirmLabel}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/ui/ContextMenu.jsx

@@ -0,0 +1,158 @@
+import { useEffect, useMemo, useRef, useState } from "react";
+
+export function ContextMenu({ x, y, items, onClose, dark }) {
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#1c2128" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      hover: dark ? "#262c36" : "#f3f4f6",
+      danger: dark ? "#f85149" : "#cf222e",
+    }),
+    [dark]
+  );
+  useEffect(() => {
+    const h = () => onClose();
+    window.addEventListener("click", h);
+    window.addEventListener("contextmenu", h);
+    return () => {
+      window.removeEventListener("click", h);
+      window.removeEventListener("contextmenu", h);
+    };
+  }, [onClose]);
+  return (
+    <div
+      style={{
+        position: "fixed",
+        left: Math.min(x, window.innerWidth - 220),
+        top: Math.min(y, window.innerHeight - 200),
+        zIndex: 3000,
+        background: T.bg,
+        border: `1px solid ${T.border}`,
+        borderRadius: 12,
+        boxShadow: "0 8px 24px rgba(0,0,0,0.25)",
+        padding: 4,
+        minWidth: 190,
+        fontFamily: "'DM Sans',sans-serif",
+      }}
+      onClick={(e) => e.stopPropagation()}
+    >
+      {items.map((item, i) =>
+        item.divider ? (
+          <div key={i} style={{ height: 1, background: T.border, margin: "4px 6px" }} />
+        ) : item.submenu ? (
+          <SubMenu key={i} item={item} T={T} onClose={onClose} />
+        ) : (
+          <button
+            key={i}
+            onClick={() => {
+              item.action();
+              onClose();
+            }}
+            style={{
+              display: "flex",
+              alignItems: "center",
+              gap: 10,
+              width: "100%",
+              padding: "8px 12px",
+              borderRadius: 8,
+              border: "none",
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+              background: "transparent",
+              color: item.danger ? T.danger : T.text,
+              textAlign: "left",
+            }}
+            onMouseEnter={(e) => (e.currentTarget.style.background = T.hover)}
+            onMouseLeave={(e) => (e.currentTarget.style.background = "transparent")}
+          >
+            {item.icon && <span style={{ display: "flex", opacity: 0.7 }}>{item.icon}</span>}
+            {item.label}
+          </button>
+        )
+      )}
+    </div>
+  );
+}
+
+function SubMenu({ item, T, onClose }) {
+  const [open, setOpen] = useState(false);
+  return (
+    <div
+      style={{ position: "relative" }}
+      onMouseEnter={() => setOpen(true)}
+      onMouseLeave={() => setOpen(false)}
+    >
+      <div
+        style={{
+          display: "flex",
+          alignItems: "center",
+          gap: 10,
+          width: "100%",
+          padding: "8px 12px",
+          borderRadius: 8,
+          fontSize: 13,
+          fontWeight: 500,
+          color: T.text,
+          cursor: "pointer",
+          background: open ? T.hover : "transparent",
+        }}
+      >
+        {item.icon && <span style={{ display: "flex", opacity: 0.7 }}>{item.icon}</span>}
+        {item.label}
+        <span style={{ marginLeft: "auto", fontSize: 10, opacity: 0.5 }}>▸</span>
+      </div>
+      {open && (
+        <div
+          style={{
+            position: "absolute",
+            left: "100%",
+            top: 0,
+            background: T.bg,
+            border: `1px solid ${T.border}`,
+            borderRadius: 10,
+            boxShadow: "0 8px 20px rgba(0,0,0,0.2)",
+            padding: 4,
+            minWidth: 160,
+            zIndex: 10,
+          }}
+        >
+          {item.submenu.map((sub, j) => (
+            <button
+              key={j}
+              onClick={() => {
+                sub.action();
+                onClose();
+              }}
+              style={{
+                display: "flex",
+                alignItems: "center",
+                gap: 8,
+                width: "100%",
+                padding: "7px 12px",
+                borderRadius: 6,
+                border: "none",
+                cursor: "pointer",
+                fontSize: 12,
+                fontWeight: 500,
+                background: "transparent",
+                color: T.text,
+                textAlign: "left",
+              }}
+              onMouseEnter={(e) => (e.currentTarget.style.background = T.hover)}
+              onMouseLeave={(e) => (e.currentTarget.style.background = "transparent")}
+            >
+              {sub.colorDot && (
+                <div
+                  style={{ width: 12, height: 8, borderRadius: 2, background: sub.colorDot, flexShrink: 0 }}
+                />
+              )}
+              {sub.label}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/ui/NotebookCover.jsx

@@ -0,0 +1,242 @@
+import { useState } from "react";
+import { COVERS } from "./constants.jsx";
+
+/* ═══════ NOTEBOOK COVER ═══════ */
+export function NotebookCover({
+  notebook,
+  noteCount,
+  onClick,
+  onContextMenu,
+  isActive,
+  isDragOver,
+  draggable,
+  onDragStart,
+  onDragEnd,
+  onDragOver,
+  onDrop,
+}) {
+  const cover = COVERS[notebook.cover % COVERS.length];
+  const [hovered, setHovered] = useState(false);
+  return (
+    <button
+      onClick={onClick}
+      onContextMenu={onContextMenu}
+      draggable={draggable}
+      onDragStart={onDragStart}
+      onDragEnd={onDragEnd}
+      onDragOver={onDragOver}
+      onDrop={onDrop}
+      onMouseEnter={() => setHovered(true)}
+      onMouseLeave={() => setHovered(false)}
+      style={{
+        display: "flex",
+        flexDirection: "column",
+        alignItems: "center",
+        gap: 10,
+        background: "none",
+        border: "none",
+        cursor: "pointer",
+        transition: "transform .22s cubic-bezier(.4,0,.2,1),opacity .2s",
+        transform: hovered ? "translateY(-6px) scale(1.03)" : isDragOver ? "scale(1.06)" : "none",
+        opacity: isDragOver ? 0.6 : 1,
+      }}
+    >
+      <div style={{ position: "relative", width: 156, height: 210, perspective: 800 }}>
+        <div
+          style={{
+            position: "absolute",
+            bottom: -5,
+            left: 10,
+            right: 10,
+            height: 14,
+            background: "rgba(0,0,0,0.25)",
+            borderRadius: "50%",
+            filter: "blur(8px)",
+            opacity: hovered ? 0.5 : 0.3,
+          }}
+        />
+        <div
+          style={{
+            position: "absolute",
+            left: 0,
+            top: 2,
+            bottom: 2,
+            width: 18,
+            background: cover.spine,
+            borderRadius: "4px 0 0 4px",
+            boxShadow: "inset -2px 0 4px rgba(0,0,0,0.3)",
+            zIndex: 2,
+          }}
+        >
+          {[12, 18].map((t) => (
+            <div
+              key={t}
+              style={{
+                position: "absolute",
+                top: t,
+                left: 3,
+                right: 3,
+                height: 1,
+                background: "rgba(255,255,255,0.1)",
+              }}
+            />
+          ))}
+          {[12, 18].map((t) => (
+            <div
+              key={"b" + t}
+              style={{
+                position: "absolute",
+                bottom: t,
+                left: 3,
+                right: 3,
+                height: 1,
+                background: "rgba(255,255,255,0.1)",
+              }}
+            />
+          ))}
+        </div>
+        <div
+          style={{
+            position: "absolute",
+            right: 2,
+            top: 8,
+            bottom: 8,
+            width: 5,
+            background: "linear-gradient(90deg,#e8e0d4,#f5f0e8,#e8e0d4)",
+            borderRadius: "0 2px 2px 0",
+            zIndex: 1,
+          }}
+        />
+        <div
+          style={{
+            position: "absolute",
+            left: 14,
+            top: 0,
+            right: 0,
+            bottom: 0,
+            background: cover.bg,
+            borderRadius: "2px 8px 8px 2px",
+            boxShadow: isActive
+              ? `0 4px 20px rgba(0,0,0,0.3),0 0 0 3px ${cover.accent}88`
+              : "0 4px 16px rgba(0,0,0,0.2)",
+            overflow: "hidden",
+            zIndex: 3,
+          }}
+        >
+          <div
+            style={{
+              position: "absolute",
+              inset: 0,
+              background:
+                "repeating-linear-gradient(45deg,transparent,transparent 30px,rgba(255,255,255,0.015) 30px,rgba(255,255,255,0.015) 60px)",
+            }}
+          />
+          <div
+            style={{
+              position: "absolute",
+              top: 0,
+              left: 0,
+              right: 0,
+              height: 3,
+              background: cover.accent,
+              opacity: 0.7,
+            }}
+          />
+          <div
+            style={{
+              position: "absolute",
+              top: 28,
+              left: "50%",
+              transform: "translateX(-50%)",
+              width: 50,
+              height: 50,
+              borderRadius: "50%",
+              border: `1.5px solid ${cover.accent}44`,
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "center",
+            }}
+          >
+            <div
+              style={{ width: 30, height: 30, borderRadius: "50%", border: `1px solid ${cover.accent}33` }}
+            />
+          </div>
+          <div
+            style={{
+              position: "absolute",
+              top: 90,
+              left: 8,
+              right: 8,
+              display: "flex",
+              flexDirection: "column",
+              alignItems: "center",
+              gap: 4,
+            }}
+          >
+            <div
+              style={{
+                width: "100%",
+                padding: "6px 4px",
+                borderTop: `1px solid ${cover.accent}33`,
+                borderBottom: `1px solid ${cover.accent}33`,
+                textAlign: "center",
+              }}
+            >
+              <span
+                style={{
+                  color: "#fff",
+                  fontSize: notebook.name.length > 12 ? 12 : 14,
+                  fontWeight: 600,
+                  fontFamily: "'Newsreader',Georgia,serif",
+                  textShadow: "0 1px 4px rgba(0,0,0,0.4)",
+                  display: "-webkit-box",
+                  WebkitLineClamp: 2,
+                  WebkitBoxOrient: "vertical",
+                  overflow: "hidden",
+                  wordBreak: "break-word",
+                }}
+              >
+                {notebook.name}
+              </span>
+            </div>
+            <div style={{ display: "flex", gap: 3 }}>
+              {[0, 1, 2].map((i) => (
+                <div
+                  key={i}
+                  style={{ width: 2.5, height: 2.5, borderRadius: "50%", background: cover.accent + "55" }}
+                />
+              ))}
+            </div>
+          </div>
+          <div
+            style={{
+              position: "absolute",
+              bottom: 0,
+              left: 0,
+              right: 0,
+              height: 3,
+              background: cover.accent,
+              opacity: 0.7,
+            }}
+          />
+        </div>
+      </div>
+      <div style={{ textAlign: "center", maxWidth: 156 }}>
+        <div
+          style={{
+            fontSize: 13,
+            fontWeight: 600,
+            overflow: "hidden",
+            textOverflow: "ellipsis",
+            whiteSpace: "nowrap",
+          }}
+        >
+          {notebook.name}
+        </div>
+        <div style={{ fontSize: 11, opacity: 0.5, marginTop: 1 }}>
+          {noteCount} {noteCount === 1 ? "note" : "notes"}
+        </div>
+      </div>
+    </button>
+  );
+}

frontend/src/ui/NotebookModals.jsx

@@ -0,0 +1,273 @@
+import { useMemo, useState } from "react";
+import { COVERS } from "./constants.jsx";
+
+export function EditNotebookModal({ notebook, onClose, onSave, dark }) {
+  const [name, setName] = useState(notebook.name);
+  const [sel, setSel] = useState(notebook.cover);
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      active: dark ? "#388bfd" : "#0969da",
+    }),
+    [dark]
+  );
+  return (
+    <div
+      style={{
+        position: "fixed",
+        inset: 0,
+        background: "rgba(0,0,0,0.55)",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        zIndex: 1000,
+        backdropFilter: "blur(6px)",
+      }}
+      onClick={onClose}
+    >
+      <div
+        style={{
+          background: T.bg,
+          borderRadius: 20,
+          padding: 30,
+          width: 460,
+          maxWidth: "92vw",
+          boxShadow: "0 24px 48px rgba(0,0,0,0.3)",
+          border: `1px solid ${T.border}`,
+        }}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <h3
+          style={{
+            margin: "0 0 22px",
+            color: T.text,
+            fontSize: 18,
+            fontWeight: 600,
+            fontFamily: "'Newsreader',Georgia,serif",
+          }}
+        >
+          Edit Notebook
+        </h3>
+        <input
+          type="text"
+          value={name}
+          onChange={(e) => setName(e.target.value)}
+          autoFocus
+          style={{
+            width: "100%",
+            padding: "10px 14px",
+            borderRadius: 10,
+            border: `1px solid ${T.border}`,
+            background: dark ? "#0d1117" : "#f6f8fa",
+            color: T.text,
+            fontSize: 14,
+            outline: "none",
+            marginBottom: 16,
+            boxSizing: "border-box",
+          }}
+          onKeyDown={(e) => {
+            if (e.key === "Enter" && name.trim()) onSave({ name: name.trim(), cover: sel });
+          }}
+        />
+        <div style={{ marginBottom: 22 }}>
+          <div style={{ fontSize: 12, color: T.muted, marginBottom: 8 }}>Cover style</div>
+          <div style={{ display: "grid", gridTemplateColumns: "repeat(5,1fr)", gap: 8 }}>
+            {COVERS.map((c, i) => (
+              <button
+                key={i}
+                onClick={() => setSel(i)}
+                style={{
+                  width: "100%",
+                  aspectRatio: "3/4",
+                  borderRadius: 8,
+                  background: c.bg,
+                  border: sel === i ? `3px solid ${T.active}` : "2px solid transparent",
+                  cursor: "pointer",
+                  position: "relative",
+                  overflow: "hidden",
+                }}
+              >
+                <div
+                  style={{ position: "absolute", left: 0, top: 0, bottom: 0, width: 4, background: c.spine }}
+                />
+              </button>
+            ))}
+          </div>
+        </div>
+        <div style={{ display: "flex", gap: 10, justifyContent: "flex-end" }}>
+          <button
+            onClick={onClose}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: `1px solid ${T.border}`,
+              background: "transparent",
+              color: T.text,
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Cancel
+          </button>
+          <button
+            onClick={() => {
+              if (name.trim()) onSave({ name: name.trim(), cover: sel });
+            }}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: "none",
+              background: T.active,
+              color: "#fff",
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Save
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export function CreateNotebookModal({ onClose, onCreate, dark }) {
+  const [name, setName] = useState("");
+  const [sel, setSel] = useState(0);
+  const T = useMemo(
+    () => ({
+      bg: dark ? "#161b22" : "#fff",
+      border: dark ? "#30363d" : "#d0d7de",
+      text: dark ? "#e6edf3" : "#1f2328",
+      muted: dark ? "#8b949e" : "#656d76",
+      active: dark ? "#388bfd" : "#0969da",
+    }),
+    [dark]
+  );
+  return (
+    <div
+      style={{
+        position: "fixed",
+        inset: 0,
+        background: "rgba(0,0,0,0.55)",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        zIndex: 1000,
+        backdropFilter: "blur(6px)",
+      }}
+      onClick={onClose}
+    >
+      <div
+        style={{
+          background: T.bg,
+          borderRadius: 20,
+          padding: 30,
+          width: 460,
+          maxWidth: "92vw",
+          boxShadow: "0 24px 48px rgba(0,0,0,0.3)",
+          border: `1px solid ${T.border}`,
+        }}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <h3
+          style={{
+            margin: "0 0 22px",
+            color: T.text,
+            fontSize: 18,
+            fontWeight: 600,
+            fontFamily: "'Newsreader',Georgia,serif",
+          }}
+        >
+          New Notebook
+        </h3>
+        <input
+          type="text"
+          value={name}
+          onChange={(e) => setName(e.target.value)}
+          placeholder="Notebook name..."
+          autoFocus
+          style={{
+            width: "100%",
+            padding: "10px 14px",
+            borderRadius: 10,
+            border: `1px solid ${T.border}`,
+            background: dark ? "#0d1117" : "#f6f8fa",
+            color: T.text,
+            fontSize: 14,
+            outline: "none",
+            marginBottom: 16,
+            boxSizing: "border-box",
+          }}
+          onKeyDown={(e) => {
+            if (e.key === "Enter" && name.trim()) onCreate({ name: name.trim(), cover: sel });
+          }}
+        />
+        <div style={{ marginBottom: 22 }}>
+          <div style={{ fontSize: 12, color: T.muted, marginBottom: 8 }}>Choose cover style</div>
+          <div style={{ display: "grid", gridTemplateColumns: "repeat(5,1fr)", gap: 8 }}>
+            {COVERS.map((c, i) => (
+              <button
+                key={i}
+                onClick={() => setSel(i)}
+                style={{
+                  width: "100%",
+                  aspectRatio: "3/4",
+                  borderRadius: 8,
+                  background: c.bg,
+                  border: sel === i ? `3px solid ${T.active}` : "2px solid transparent",
+                  cursor: "pointer",
+                  position: "relative",
+                  overflow: "hidden",
+                }}
+              >
+                <div
+                  style={{ position: "absolute", left: 0, top: 0, bottom: 0, width: 4, background: c.spine }}
+                />
+              </button>
+            ))}
+          </div>
+        </div>
+        <div style={{ display: "flex", gap: 10, justifyContent: "flex-end" }}>
+          <button
+            onClick={onClose}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: `1px solid ${T.border}`,
+              background: "transparent",
+              color: T.text,
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Cancel
+          </button>
+          <button
+            onClick={() => {
+              if (name.trim()) onCreate({ name: name.trim(), cover: sel });
+            }}
+            style={{
+              padding: "8px 20px",
+              borderRadius: 10,
+              border: "none",
+              background: T.active,
+              color: "#fff",
+              cursor: "pointer",
+              fontSize: 13,
+              fontWeight: 500,
+            }}
+          >
+            Create
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/ui/Sidebar.jsx

@@ -0,0 +1,375 @@
+import { COVERS, DEFAULT_FOLDERS } from "./constants.jsx";
+import { I } from "./icons.jsx";
+import { FONT_UI } from "./theme";
+
+const SYNC_LABELS = {
+  synced: "All synced",
+  syncing: "Syncing...",
+  offline: "Offline mode",
+  pending: "Changes pending",
+};
+
+const syncColor = (status, T) => {
+  if (status === "synced") return T.success;
+  if (status === "syncing" || status === "pending") return T.warning;
+  if (status === "offline") return T.muted;
+  return T.danger;
+};
+
+const iconButton = (T) => ({
+  display: "flex",
+  alignItems: "center",
+  justifyContent: "center",
+  width: 32,
+  height: 32,
+  borderRadius: 8,
+  border: "none",
+  background: "transparent",
+  cursor: "pointer",
+  color: T.muted,
+});
+
+const folderButton = (T, active) => ({
+  display: "flex",
+  alignItems: "center",
+  gap: 10,
+  width: "100%",
+  padding: "8px 12px",
+  borderRadius: 10,
+  border: "none",
+  cursor: "pointer",
+  fontSize: 13,
+  fontWeight: 500,
+  textAlign: "left",
+  background: active ? T.sidebarActive : "transparent",
+  color: active ? T.accentText : T.textSec,
+});
+
+const countBadge = (T, color) => ({
+  marginLeft: "auto",
+  fontSize: 11,
+  color,
+  background: color === T.danger ? T.danger + "15" : T.accentSoft,
+  padding: "2px 7px",
+  borderRadius: 10,
+});
+
+/**
+ * Navigation rail: search, the built-in views, and the notebook list.
+ *
+ * On a phone it becomes a full-screen overlay; `onClose` is what the backdrop
+ * and every navigation action call so it does not stay in the way.
+ */
+export function Sidebar({
+  T,
+  dark,
+  onToggleDark,
+  isMobile,
+  open,
+  onClose,
+  searchQuery,
+  onSearchChange,
+  activeFolder,
+  onSelectFolder,
+  notebooks,
+  activeNotes,
+  trashedCount,
+  onNewNotebook,
+  onOpenAccount,
+  onNotebookContextMenu,
+  dnd,
+  canInstall,
+  onInstall,
+  syncStatus,
+  online,
+}) {
+  const notesIn = (nbId) => activeNotes.filter((n) => n.folderId === nbId).length;
+
+  return (
+    <div
+      style={{
+        position: isMobile ? "fixed" : "relative",
+        zIndex: isMobile ? 900 : 1,
+        width: isMobile ? (open ? "100vw" : 0) : open ? 260 : 0,
+        minWidth: isMobile ? 0 : open ? 260 : 0,
+        height: isMobile ? "100vh" : "auto",
+        background: T.sidebar,
+        borderRight: isMobile ? "none" : `1px solid ${T.border}`,
+        display: "flex",
+        flexDirection: "column",
+        overflow: "hidden",
+        transition: "all .25s cubic-bezier(.4,0,.2,1)",
+        fontFamily: FONT_UI,
+      }}
+    >
+      {isMobile && open && (
+        <div
+          onClick={onClose}
+          style={{ position: "absolute", inset: 0, background: "rgba(0,0,0,0.4)", zIndex: -1 }}
+        />
+      )}
+      <div
+        style={{
+          width: isMobile ? "85vw" : 260,
+          maxWidth: 320,
+          height: "100%",
+          background: T.sidebar,
+          display: "flex",
+          flexDirection: "column",
+          position: "relative",
+          zIndex: 1,
+        }}
+      >
+        <div
+          style={{
+            padding: "20px 18px 12px",
+            display: "flex",
+            alignItems: "center",
+            justifyContent: "space-between",
+          }}
+        >
+          <div style={{ display: "flex", alignItems: "center", gap: 10 }}>
+            <div
+              style={{
+                width: 32,
+                height: 32,
+                borderRadius: 10,
+                background: `linear-gradient(135deg,${T.accent},#a855f7)`,
+                display: "flex",
+                alignItems: "center",
+                justifyContent: "center",
+                fontSize: 16,
+              }}
+            >
+              ✏️
+            </div>
+            <span style={{ fontWeight: 700, fontSize: 17, color: T.text, letterSpacing: "-0.02em" }}>
+              InkNote
+            </span>
+          </div>
+          <div style={{ display: "flex", gap: 4 }}>
+            <button onClick={onToggleDark} style={iconButton(T)}>
+              {dark ? I.sun : I.moon}
+            </button>
+            <button onClick={onOpenAccount} title="Account" style={iconButton(T)}>
+              {I.user}
+            </button>
+          </div>
+        </div>
+
+        <div style={{ padding: "0 14px 12px" }}>
+          <div
+            style={{
+              display: "flex",
+              alignItems: "center",
+              gap: 8,
+              padding: "8px 12px",
+              borderRadius: 10,
+              background: T.inputBg,
+              border: `1px solid ${T.borderLight}`,
+            }}
+          >
+            <span style={{ color: T.faint }}>{I.search}</span>
+            <input
+              type="text"
+              value={searchQuery}
+              onChange={(e) => onSearchChange(e.target.value)}
+              placeholder="Search notes..."
+              style={{
+                border: "none",
+                background: "transparent",
+                outline: "none",
+                flex: 1,
+                color: T.text,
+                fontSize: 13,
+                fontFamily: FONT_UI,
+              }}
+            />
+          </div>
+        </div>
+
+        <div style={{ padding: "0 10px" }}>
+          <button
+            onClick={() => onSelectFolder("dashboard")}
+            style={{ ...folderButton(T, activeFolder === "dashboard"), padding: "9px 12px", fontWeight: 600 }}
+          >
+            <span style={{ fontSize: 15 }}>📚</span>
+            <span>Dashboard</span>
+          </button>
+        </div>
+
+        <div style={{ padding: "6px 10px 0" }}>
+          {DEFAULT_FOLDERS.map((f) => (
+            <button
+              key={f.id}
+              onClick={() => onSelectFolder(f.id)}
+              style={folderButton(T, activeFolder === f.id)}
+            >
+              <span style={{ fontSize: 14 }}>{f.icon}</span>
+              <span>{f.name}</span>
+              {f.id === "all" && <span style={countBadge(T, T.faint)}>{activeNotes.length}</span>}
+              {f.id === "trash" && trashedCount > 0 && (
+                <span style={countBadge(T, T.danger)}>{trashedCount}</span>
+              )}
+            </button>
+          ))}
+        </div>
+
+        <div style={{ padding: "14px 10px 4px" }}>
+          <div
+            style={{
+              display: "flex",
+              alignItems: "center",
+              justifyContent: "space-between",
+              padding: "0 12px",
+              marginBottom: 6,
+            }}
+          >
+            <span
+              style={{
+                fontSize: 11,
+                fontWeight: 600,
+                color: T.faint,
+                textTransform: "uppercase",
+                letterSpacing: "0.08em",
+              }}
+            >
+              Notebooks
+            </span>
+            <button
+              onClick={onNewNotebook}
+              style={{
+                display: "flex",
+                alignItems: "center",
+                justifyContent: "center",
+                width: 22,
+                height: 22,
+                borderRadius: 6,
+                border: "none",
+                background: T.accentSoft,
+                cursor: "pointer",
+                color: T.accent,
+              }}
+            >
+              {I.plus}
+            </button>
+          </div>
+          {notebooks.map((nb) => (
+            <div
+              key={nb.id}
+              draggable={!isMobile}
+              onDragStart={(e) => dnd.onDragStart(e, nb.id)}
+              onDragOver={(e) => dnd.onDragOver(e, nb.id)}
+              onDrop={(e) => dnd.onDrop(e, nb.id)}
+              onDragEnd={dnd.onDragEnd}
+              onContextMenu={(e) => onNotebookContextMenu(e, nb)}
+              style={{
+                display: "flex",
+                alignItems: "center",
+                borderRadius: 10,
+                transition: "all .15s",
+                background:
+                  dnd.overId === nb.id
+                    ? T.accentSoft
+                    : activeFolder === nb.id
+                      ? T.sidebarActive
+                      : "transparent",
+                borderTop: dnd.overId === nb.id ? `2px solid ${T.accent}` : "2px solid transparent",
+              }}
+            >
+              {!isMobile && (
+                <span
+                  style={{
+                    padding: "0 2px 0 6px",
+                    color: T.faint,
+                    cursor: "grab",
+                    display: "flex",
+                    alignItems: "center",
+                    opacity: 0.5,
+                  }}
+                >
+                  {I.grip}
+                </span>
+              )}
+              <button
+                onClick={() => onSelectFolder(nb.id)}
+                style={{
+                  display: "flex",
+                  alignItems: "center",
+                  gap: 10,
+                  flex: 1,
+                  padding: "7px 10px 7px " + (isMobile ? "10px" : "4px"),
+                  borderRadius: 10,
+                  border: "none",
+                  cursor: "pointer",
+                  fontSize: 13,
+                  fontWeight: 500,
+                  textAlign: "left",
+                  background: "transparent",
+                  color: activeFolder === nb.id ? T.accentText : T.textSec,
+                }}
+              >
+                <div
+                  style={{
+                    width: 20,
+                    height: 14,
+                    borderRadius: 3,
+                    background: COVERS[nb.cover % COVERS.length].bg,
+                    flexShrink: 0,
+                    boxShadow: "0 1px 3px rgba(0,0,0,0.2)",
+                  }}
+                />
+                <span>{nb.name}</span>
+                <span style={{ marginLeft: "auto", fontSize: 11, color: T.faint }}>{notesIn(nb.id)}</span>
+              </button>
+            </div>
+          ))}
+        </div>
+
+        <div style={{ marginTop: "auto", padding: "12px 14px", borderTop: `1px solid ${T.borderLight}` }}>
+          {canInstall && (
+            <button
+              onClick={onInstall}
+              style={{
+                display: "flex",
+                alignItems: "center",
+                gap: 8,
+                width: "100%",
+                padding: "8px 12px",
+                borderRadius: 10,
+                border: `1px solid ${T.accent}44`,
+                background: T.accentSoft,
+                cursor: "pointer",
+                color: T.accent,
+                fontSize: 12,
+                fontWeight: 600,
+                marginBottom: 8,
+              }}
+            >
+              {I.download}
+              Install App
+            </button>
+          )}
+          <div style={{ display: "flex", alignItems: "center", gap: 6, color: T.muted, fontSize: 12 }}>
+            <span style={{ color: syncColor(syncStatus, T) }}>●</span>
+            <span>{SYNC_LABELS[syncStatus] || "Sync error"}</span>
+            {!online && (
+              <span
+                style={{
+                  fontSize: 10,
+                  padding: "2px 6px",
+                  borderRadius: 6,
+                  background: T.faint + "22",
+                  color: T.faint,
+                  marginLeft: "auto",
+                }}
+              >
+                offline
+              </span>
+            )}
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/ui/constants.jsx

@@ -0,0 +1,47 @@
+/** Shared visual constants: palette, notebook covers, sidebar folders. */
+
+export const COLORS = [
+  "#0d1117",
+  "#e94560",
+  "#0f3460",
+  "#533483",
+  "#e07c24",
+  "#21bf73",
+  "#fd5e53",
+  "#3282b8",
+  "#ff6b6b",
+  "#4ecdc4",
+  "#f7dc6f",
+  "#bb8fce",
+  "#85c1e9",
+  "#f8c471",
+  "#82e0aa",
+  "#f1948a",
+  "#aeb6bf",
+  "#ffffff",
+  "#f39c12",
+  "#000000",
+];
+
+export const COVERS = [
+  { bg: "linear-gradient(135deg,#0f0c29,#302b63,#24243e)", spine: "#1a1540", accent: "#6c63ff" },
+  { bg: "linear-gradient(135deg,#1a1a2e,#16213e,#0f3460)", spine: "#0a1628", accent: "#4fc3f7" },
+  { bg: "linear-gradient(135deg,#134e5e,#71b280)", spine: "#0e3d4a", accent: "#a5d6a7" },
+  { bg: "linear-gradient(135deg,#8e2de2,#4a00e0)", spine: "#3a0099", accent: "#ce93d8" },
+  { bg: "linear-gradient(135deg,#fc4a1a,#f7b733)", spine: "#c43d15", accent: "#ffe082" },
+  { bg: "linear-gradient(135deg,#c94b4b,#4b134f)", spine: "#3d0f40", accent: "#f48fb1" },
+  { bg: "linear-gradient(135deg,#11998e,#38ef7d)", spine: "#0d7a71", accent: "#b9f6ca" },
+  { bg: "linear-gradient(135deg,#373b44,#4286f4)", spine: "#2a2e35", accent: "#90caf9" },
+  { bg: "linear-gradient(135deg,#141e30,#243b55)", spine: "#0e1520", accent: "#78909c" },
+  { bg: "linear-gradient(135deg,#f12711,#f5af19)", spine: "#c01f0d", accent: "#fff59d" },
+  { bg: "linear-gradient(135deg,#2c3e50,#3498db)", spine: "#1e2b38", accent: "#81d4fa" },
+  { bg: "linear-gradient(135deg,#0f2027,#203a43,#2c5364)", spine: "#0a171c", accent: "#80cbc4" },
+  { bg: "linear-gradient(135deg,#aa4b6b,#6b6b83,#3b8d99)", spine: "#7a3550", accent: "#f48fb1" },
+  { bg: "linear-gradient(135deg,#1f1c2c,#928dab)", spine: "#15131f", accent: "#b39ddb" },
+  { bg: "linear-gradient(135deg,#654ea3,#eaafc8)", spine: "#4e3c7e", accent: "#f8bbd0" },
+];
+export const DEFAULT_FOLDERS = [
+  { id: "all", name: "All Notes", icon: "📋" },
+  { id: "starred", name: "Starred", icon: "⭐" },
+  { id: "trash", name: "Trash", icon: "🗑️" },
+];

frontend/src/ui/format.ts

@@ -0,0 +1,8 @@
+/** Timestamp shown on note cards and list rows. */
+export const fmtDate = (d: string): string =>
+  new Date(d).toLocaleDateString("en-US", {
+    month: "short",
+    day: "numeric",
+    hour: "2-digit",
+    minute: "2-digit",
+  });

frontend/src/ui/icons.jsx

@@ -0,0 +1,469 @@
+/** The app's icon set. Inline SVG so they inherit `currentColor`. */
+
+export const I = {
+  plus: (
+    <svg
+      width="18"
+      height="18"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2.2"
+      strokeLinecap="round"
+    >
+      <line x1="12" y1="5" x2="12" y2="19" />
+      <line x1="5" y1="12" x2="19" y2="12" />
+    </svg>
+  ),
+  search: (
+    <svg
+      width="16"
+      height="16"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <circle cx="11" cy="11" r="8" />
+      <line x1="21" y1="21" x2="16.65" y2="16.65" />
+    </svg>
+  ),
+  bold: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2.5"
+      strokeLinecap="round"
+    >
+      <path d="M6 4h8a4 4 0 0 1 4 4 4 4 0 0 1-4 4H6z" />
+      <path d="M6 12h9a4 4 0 0 1 4 4 4 4 0 0 1-4 4H6z" />
+    </svg>
+  ),
+  italic: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <line x1="19" y1="4" x2="10" y2="4" />
+      <line x1="14" y1="20" x2="5" y2="20" />
+      <line x1="15" y1="4" x2="9" y2="20" />
+    </svg>
+  ),
+  underline: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M6 3v7a6 6 0 0 0 6 6 6 6 0 0 0 6-6V3" />
+      <line x1="4" y1="21" x2="20" y2="21" />
+    </svg>
+  ),
+  list: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <line x1="8" y1="6" x2="21" y2="6" />
+      <line x1="8" y1="12" x2="21" y2="12" />
+      <line x1="8" y1="18" x2="21" y2="18" />
+      <circle cx="4" cy="6" r="1" fill="currentColor" />
+      <circle cx="4" cy="12" r="1" fill="currentColor" />
+      <circle cx="4" cy="18" r="1" fill="currentColor" />
+    </svg>
+  ),
+  listOrd: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <line x1="10" y1="6" x2="21" y2="6" />
+      <line x1="10" y1="12" x2="21" y2="12" />
+      <line x1="10" y1="18" x2="21" y2="18" />
+      <text x="2" y="8" fontSize="8" fill="currentColor" stroke="none" fontFamily="sans-serif">
+        1
+      </text>
+      <text x="2" y="14" fontSize="8" fill="currentColor" stroke="none" fontFamily="sans-serif">
+        2
+      </text>
+      <text x="2" y="20" fontSize="8" fill="currentColor" stroke="none" fontFamily="sans-serif">
+        3
+      </text>
+    </svg>
+  ),
+  check: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <rect x="3" y="3" width="18" height="18" rx="3" />
+      <path d="M9 12l2 2 4-4" />
+    </svg>
+  ),
+  trash: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="3 6 5 6 21 6" />
+      <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
+    </svg>
+  ),
+  star: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+      strokeLinejoin="round"
+    >
+      <polygon points="12 2 15.09 8.26 22 9.27 17 14.14 18.18 21.02 12 17.77 5.82 21.02 7 14.14 2 9.27 8.91 8.26 12 2" />
+    </svg>
+  ),
+  starFill: (
+    <svg width="15" height="15" viewBox="0 0 24 24" fill="currentColor" stroke="currentColor" strokeWidth="2">
+      <polygon points="12 2 15.09 8.26 22 9.27 17 14.14 18.18 21.02 12 17.77 5.82 21.02 7 14.14 2 9.27 8.91 8.26 12 2" />
+    </svg>
+  ),
+  pen: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M12 19l7-7 3 3-7 7-3-3z" />
+      <path d="M18 13l-1.5-7.5L2 2l3.5 14.5L13 18l5-5z" />
+      <path d="M2 2l7.586 7.586" />
+      <circle cx="11" cy="11" r="2" />
+    </svg>
+  ),
+  eraser: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M20 20H7L3 16l9-9 8 8-4 4" />
+      <path d="M6 11l8 8" />
+    </svg>
+  ),
+  highlight: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M15.5 2.5L22 9l-6 6-7-7 6.5-5.5z" />
+      <path d="M9 8l-5 5 4 4 5-5" />
+      <path d="M4 13l-2 7 7-2" />
+    </svg>
+  ),
+  undo: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="1 4 1 10 7 10" />
+      <path d="M3.51 15a9 9 0 1 0 2.13-9.36L1 10" />
+    </svg>
+  ),
+  redo: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="23 4 23 10 17 10" />
+      <path d="M20.49 15a9 9 0 1 1-2.12-9.36L23 10" />
+    </svg>
+  ),
+  sun: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <circle cx="12" cy="12" r="5" />
+      <line x1="12" y1="1" x2="12" y2="3" />
+      <line x1="12" y1="21" x2="12" y2="23" />
+      <line x1="4.22" y1="4.22" x2="5.64" y2="5.64" />
+      <line x1="18.36" y1="18.36" x2="19.78" y2="19.78" />
+      <line x1="1" y1="12" x2="3" y2="12" />
+      <line x1="21" y1="12" x2="23" y2="12" />
+      <line x1="4.22" y1="19.78" x2="5.64" y2="18.36" />
+      <line x1="18.36" y1="5.64" x2="19.78" y2="4.22" />
+    </svg>
+  ),
+  moon: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z" />
+    </svg>
+  ),
+  menu: (
+    <svg
+      width="20"
+      height="20"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <line x1="3" y1="6" x2="21" y2="6" />
+      <line x1="3" y1="12" x2="21" y2="12" />
+      <line x1="3" y1="18" x2="21" y2="18" />
+    </svg>
+  ),
+  text: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="4 7 4 4 20 4 20 7" />
+      <line x1="9" y1="20" x2="15" y2="20" />
+      <line x1="12" y1="4" x2="12" y2="20" />
+    </svg>
+  ),
+  draw: (
+    <svg
+      width="17"
+      height="17"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M17 3a2.828 2.828 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5L17 3z" />
+    </svg>
+  ),
+  edit: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
+      <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z" />
+    </svg>
+  ),
+  move: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M15 3h4a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2h-4" />
+      <polyline points="10 17 15 12 10 7" />
+      <line x1="15" y1="12" x2="3" y2="12" />
+    </svg>
+  ),
+  restore: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="1 4 1 10 7 10" />
+      <path d="M3.51 15a9 9 0 1 0 2.13-9.36L1 10" />
+    </svg>
+  ),
+  grip: (
+    <svg width="12" height="12" viewBox="0 0 24 24" fill="currentColor">
+      <circle cx="9" cy="5" r="2" />
+      <circle cx="15" cy="5" r="2" />
+      <circle cx="9" cy="12" r="2" />
+      <circle cx="15" cy="12" r="2" />
+      <circle cx="9" cy="19" r="2" />
+      <circle cx="15" cy="19" r="2" />
+    </svg>
+  ),
+  logout: (
+    <svg
+      width="15"
+      height="15"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4" />
+      <polyline points="16 17 21 12 16 7" />
+      <line x1="21" y1="12" x2="9" y2="12" />
+    </svg>
+  ),
+  user: (
+    <svg
+      width="16"
+      height="16"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2" />
+      <circle cx="12" cy="7" r="4" />
+    </svg>
+  ),
+  x: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <line x1="18" y1="6" x2="6" y2="18" />
+      <line x1="6" y1="6" x2="18" y2="18" />
+    </svg>
+  ),
+  history: (
+    <svg
+      width="16"
+      height="16"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+      strokeLinejoin="round"
+    >
+      <path d="M3 3v5h5" />
+      <path d="M3.05 13A9 9 0 1 0 6 5.3L3 8" />
+      <path d="M12 7v5l4 2" />
+    </svg>
+  ),
+  save: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z" />
+      <polyline points="17 21 17 13 7 13 7 21" />
+      <polyline points="7 3 7 8 15 8" />
+    </svg>
+  ),
+  download: (
+    <svg
+      width="14"
+      height="14"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4" />
+      <polyline points="7 10 12 15 17 10" />
+      <line x1="12" y1="15" x2="12" y2="3" />
+    </svg>
+  ),
+  back: (
+    <svg
+      width="16"
+      height="16"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+    >
+      <polyline points="15 18 9 12 15 6" />
+    </svg>
+  ),
+};

frontend/src/ui/theme.ts

@@ -0,0 +1,80 @@
+/**
+ * The application palette.
+ *
+ * Colours live here rather than inline so that a change to, say, the danger red
+ * happens in one place. Modal components still carry small local palettes of
+ * their own — their key names mean different things (a modal's `bg` is a raised
+ * surface, the app's `bg` is the page behind it), so they are deliberately not
+ * folded in here.
+ */
+
+export interface Theme {
+  bg: string;
+  sidebar: string;
+  sidebarActive: string;
+  card: string;
+  toolbar: string;
+  border: string;
+  borderLight: string;
+  text: string;
+  textSec: string;
+  muted: string;
+  faint: string;
+  accent: string;
+  accentSoft: string;
+  accentText: string;
+  danger: string;
+  success: string;
+  warning: string;
+  inputBg: string;
+  dashBg: string;
+}
+
+const DARK: Theme = {
+  bg: "#0d1117",
+  sidebar: "#010409",
+  sidebarActive: "#161b22",
+  card: "#161b22",
+  toolbar: "#161b22",
+  border: "#30363d",
+  borderLight: "#21262d",
+  text: "#e6edf3",
+  textSec: "#c9d1d9",
+  muted: "#8b949e",
+  faint: "#484f58",
+  accent: "#388bfd",
+  accentSoft: "#388bfd22",
+  accentText: "#58a6ff",
+  danger: "#f85149",
+  success: "#3fb950",
+  warning: "#d29922",
+  inputBg: "#0d1117",
+  dashBg: "#0d1117",
+};
+
+const LIGHT: Theme = {
+  bg: "#f6f8fa",
+  sidebar: "#ffffff",
+  sidebarActive: "#eef2ff",
+  card: "#ffffff",
+  toolbar: "#ffffff",
+  border: "#d0d7de",
+  borderLight: "#e5e7eb",
+  text: "#1f2328",
+  textSec: "#424a53",
+  muted: "#656d76",
+  faint: "#afb8c1",
+  accent: "#0969da",
+  accentSoft: "#0969da18",
+  accentText: "#0550ae",
+  danger: "#cf222e",
+  success: "#1a7f37",
+  warning: "#9a6700",
+  inputBg: "#f6f8fa",
+  dashBg: "#f0f2f5",
+};
+
+export const makeTheme = (dark: boolean): Theme => (dark ? DARK : LIGHT);
+
+export const FONT_UI = "'DM Sans',sans-serif";
+export const FONT_SERIF = "'Newsreader',Georgia,serif";

frontend/tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "jsx": "react-jsx",
+
+    "strict": true,
+    "noUncheckedIndexedAccess": true,
+    "noImplicitOverride": true,
+    "noFallthroughCasesInSwitch": true,
+
+    "allowJs": true,
+    "checkJs": false,
+    "noEmit": true,
+    "skipLibCheck": true,
+    "isolatedModules": true,
+    "resolveJsonModule": true,
+    "verbatimModuleSyntax": false,
+    "allowImportingTsExtensions": true
+  },
+  "include": ["src"]
+}

frontend/vite.config.js

@@ -1,10 +1,20 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
 
+// In Docker the backend is reachable under its service name, locally under localhost.
+const API_TARGET = process.env.VITE_API_TARGET || 'http://localhost:4000'
+
 export default defineConfig({
   plugins: [react()],
   server: {
     host: '0.0.0.0',
-    port: 3000,
+    port: 5173,
+    strictPort: true,
+    // Needed for file-watching to work through a bind mount inside Docker.
+    watch: { usePolling: true, interval: 300 },
+    proxy: {
+      '/api': { target: API_TARGET, changeOrigin: true },
+      '/ws': { target: API_TARGET, changeOrigin: true, ws: true },
+    },
   },
 })

frontend/vitest.config.js

@@ -0,0 +1,9 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    environment: "jsdom",
+    include: ["src/**/*.test.{js,ts}"],
+    setupFiles: ["src/test/setup.js"],
+  },
+});

readme.md

@@ -7,7 +7,12 @@ A cross-platform note-taking application with rich text editing, freehand drawin
 ## Features
 
 ### Core
-- **Rich Text Notes** — Bold, italic, underline, headings, bullet/numbered lists, checkboxes
+- **Rich Text Notes** — Bold, italic, underline, headings, bullet/numbered lists, task lists, quotes, code blocks
+- **Tables** — Insert, resize columns, add/remove rows and columns, merge cells, toggle header row
+- **Note Links** — Type `@` to link to another note or notebook; every note shows what links back to it
+- **Version History** — Past states of every note, restorable; restoring is itself reversible
+- **Full-Text Search** — Searches note bodies, not just titles, and works offline
+- **Image Attachments** — Pasted images are stored as deduplicated blobs, not inlined into the note
 - **Freehand Drawing** — Pen, highlighter, eraser with adjustable thickness and color palette (20 colors, 7 pen sizes)
 - **Undo/Redo** — Full history stack for drawing operations
 - **PDF Import & Annotation** — Import PDFs, overlay drawing/highlighting, persistent annotations
@@ -20,7 +25,8 @@ A cross-platform note-taking application with rich text editing, freehand drawin
 - **Conflict-Aware Sync** — Vector clock–based conflict detection; notifies user of merge conflicts
 - **WebSocket Real-Time Push** — Changes appear on other devices instantly
 - **Encrypted at Rest** — AES-256-CBC encryption for all note content on the server
-- **JWT Authentication** — Secure user accounts with bcrypt password hashing
+- **JWT Authentication** — Username + password accounts with bcrypt password hashing
+- **Vector Drawings** — Strokes are stored as vectors in one canonical page space, so a drawing looks identical on every screen and stays sharp at any pixel density
 
 ### Architecture
 - **Self-Hosted Backend** — Node.js + Express + SQLite (or PostgreSQL)
@@ -33,43 +39,75 @@ A cross-platform note-taking application with rich text editing, freehand drawin
 
 ```
 inknote/
-├── note-app.jsx              # Full React UI (artifact / web)
+├── docker-compose.yml        # Deploy from the Gitea registry
-├── docker-compose.yml        # Container orchestration
+├── docker-compose.dev.yml    # Build from source for local work
+├── build.sh                  # Build & push images to Gitea
 ├── backend/
 │   ├── server.js             # Express API + WebSocket server
 │   ├── sync-client.js        # Client-side sync engine library
 │   ├── package.json          # Node dependencies
 │   ├── Dockerfile            # Server container
 │   └── .env.example          # Environment variable template
-└── README.md                 # This file
+├── frontend/
+│   ├── src/
+│   │   ├── App.jsx           # Root: where the user is, which dialog is open
+│   │   ├── types.ts          # Shapes shared by server, IndexedDB and UI
+│   │   ├── syncEngine.ts     # Offline-first sync + API client
+│   │   ├── offlineStore.ts   # IndexedDB wrapper
+│   │   ├── search.ts         # Local full-text index
+│   │   ├── hooks/            # Note data, search, layout, history, drag
+│   │   ├── ui/               # Sidebar, dialogs, icons, palette
+│   │   ├── features/notes/   # List, editor pane, version history
+│   │   ├── features/notebooks/ # Dashboard
+│   │   ├── features/drawing/ # Canonical stroke model + render layer
+│   │   └── editor/           # TipTap schema, toolbar, note links, attachments
+│   ├── public/sw.js          # PWA service worker
+│   ├── nginx.conf            # Static serving + API/WS proxy
+│   └── dockerfile            # Web container
+└── readme.md                 # This file
 ```
 
 ---
 
 ## Quick Start
 
-### 1. Run the UI (Web / Artifact)
+### Where the data lives
 
-The `note-app.jsx` file is a self-contained React component. It runs directly as a Claude artifact, or you can embed it in any React project:
+Both compose files use **bind mounts**, not named volumes, so everything sits in
+a plain directory on the Docker host and is picked up by whatever backs that
+host up:
 
-```jsx
+```
-import NoteApp from './note-app';
+$INKNOTE_DATA_DIR/
-
+├── db/        # inknote.db — notes, drawings, version history
-function App() {
+└── uploads/   # legacy raster drawings, PDFs
-  return <NoteApp />;
-}
 ```
 
-### 2. Run the Backend
+Default is `./data` for development and `/srv/inknote` in production; override
+with `INKNOTE_DATA_DIR`. The container runs as uid/gid `1000` so the files stay
+owned by a normal user — set `INKNOTE_UID` / `INKNOTE_GID` if yours differ, and
+create the directory with matching ownership before the first start.
+
+> Back up the `.env` holding `ENCRYPTION_KEY` too. Note content is encrypted at
+> rest, so a copy of the database without that key cannot be read.
+
+### 1. Local development (Docker)
 
 ```bash
-cd backend
+# Generate secrets once
-cp .env.example .env        # Edit secrets!
+printf 'JWT_SECRET=%s\nENCRYPTION_KEY=%s\n' "$(openssl rand -base64 32)" "$(openssl rand -hex 32)" > .env
-npm install
+
-npm start                   # → http://localhost:4000
+# Build and run backend + nginx-served frontend
+docker compose -f docker-compose.dev.yml up -d --build      # → http://localhost:3000
+
+# Same, plus a Vite dev server with hot reload
+docker compose -f docker-compose.dev.yml --profile dev up -d --build   # → http://localhost:5173
 ```
 
-### 3. Docker Deployment
+`docker-compose.dev.yml` builds from source and uses its own volumes, so it never
+touches production data.
+
+### 2. Docker Deployment
 
 ```bash
 # Generate a secure encryption key
@@ -89,8 +127,15 @@ The server runs on port `4000`, the web UI on port `3000`.
 
 | Method | Endpoint              | Body                          | Response            |
 |--------|-----------------------|-------------------------------|---------------------|
-| POST   | `/api/auth/register`  | `{email, password, displayName}` | `{token, user}`  |
+| POST   | `/api/auth/register`  | `{username, password, displayName}` | `{token, user}` |
-| POST   | `/api/auth/login`     | `{email, password}`           | `{token, user}`     |
+| POST   | `/api/auth/login`     | `{username, password}`        | `{token, user}`     |
+| GET    | `/api/auth/me`        | —                             | `{id, username, displayName}` |
+| PUT    | `/api/auth/username`  | `{newUsername, password}`     | updated user        |
+| PUT    | `/api/auth/password`  | `{currentPassword, newPassword}` | `{success}`      |
+
+Usernames are 3–32 characters of letters, digits, `.`, `_` or `-`, and match case-insensitively.
+Servers created before this carried e-mail logins; on first start they migrate automatically,
+deriving each username from the local part of the address (logged to the console).
 
 ### Notebooks
 
@@ -108,9 +153,11 @@ The server runs on port `4000`, the web UI on port `3000`.
 | GET    | `/api/notes`              | List all notes (metadata)     |
 | GET    | `/api/notes/:id`          | Get note with decrypted content |
 | POST   | `/api/notes`              | Create note                   |
-| PUT    | `/api/notes/:id`          | Update note (conflict-aware)  |
+| PUT    | `/api/notes/:id`          | Update note (`{content, links}`) |
+| GET    | `/api/notes/:id/backlinks`| Notes linking to this one     |
+| GET    | `/api/links`              | Every link, for backlink counts |
 | DELETE | `/api/notes/:id`          | Soft-delete note              |
-| PUT    | `/api/notes/:id/drawing`  | Save drawing data (base64)    |
+| PUT    | `/api/notes/:id/drawing`  | Save vector strokes           |
 | POST   | `/api/notes/pdf`          | Upload PDF (multipart/form)   |
 
 ### Sync
@@ -138,7 +185,7 @@ import { SyncEngine } from './sync-client';
 const sync = new SyncEngine('https://your-server.com', 'device-abc');
 
 // Authenticate
-await sync.authenticate('user@example.com', 'password');
+await sync.authenticate('username', 'password');
 
 // Listen for events
 sync.on('status', (status) => console.log('Sync:', status));
@@ -159,11 +206,196 @@ await sync.createNote({ type: 'text', title: 'Hello', content: '<p>World</p>' })
 await sync.updateNote('note-id', { title: 'Updated' });
 await sync.deleteNote('note-id');
 await sync.uploadPDF(fileBlob);
-await sync.saveDrawing('note-id', canvasDataUrl);
+await sync.saveDrawing('note-id', strokeDoc);
 ```
 
 ---
 
+## Working on the frontend
+
+```bash
+npm run test        # Vitest — store, search and content migration
+npm run typecheck   # tsc --noEmit
+npm run format      # Prettier
+npm run build       # production bundle
+```
+
+TypeScript is enabled with `allowJs`, so `.js` and `.ts` coexist and modules can
+be converted one at a time. The whole data layer is typed — `types`,
+`offlineStore`, `search`, `editor/content` and `syncEngine` — because that is
+where the bugs have been: every serious one so far has been a shape bug, or a
+failure distinguished by comparing an error's `.message` to a magic string.
+Failures now carry a typed `SyncError.code`; `.message` still holds the same
+string, so the remaining JavaScript callers are unaffected.
+
+The 81 unit tests concentrate on the same places, and several exist because the
+bug they cover actually happened:
+
+- a queue entry that fails must stay queued, with an attempt counter
+- `fullSync` must not drop notes created offline
+- `hasPendingWrites` must cover the debounce window, not just requests in flight
+- v1 note bodies must migrate without losing task state or smuggling in markup
+
+### How the frontend is arranged
+
+`App.jsx` holds only *where the user is* — the open notebook, the open note, the
+search box, whichever dialog is up — and hands each of the three panes what it
+needs. Everything else lives behind a hook:
+
+| Hook | Owns |
+| --- | --- |
+| `useNoteData` | notes, notebooks, bodies, every mutation, background sync |
+| `useSearchIndex` | the local index and the background backfill that fills it |
+| `useResponsive` | phone vs desktop, sidebar and which pane a phone shows |
+| `useNavigationHistory` | mapping the current location onto browser history |
+| `useNotebookDnd` | drag-to-reorder, shared by sidebar and dashboard |
+| `usePwaInstall` | the browser's install offer |
+
+`useNoteData` deliberately has no confirmation prompts in it: whether to ask
+before deleting something is a question for the interface, not the store. The
+panes (`Sidebar`, `Dashboard`, `NoteList`, `EditorPane`) take props and hold no
+state of their own, so they can be read on their own.
+
+---
+
+## Note Content
+
+The body of a note is a **TipTap/ProseMirror document** stored as JSON:
+
+```json
+{ "v": 2, "doc": { "type": "doc", "content": [ … ] } }
+```
+
+Tables, task lists and note links are real nodes rather than HTML that happened
+to survive `document.execCommand`. Notes written before this were
+`{ html, tasks }`; they are converted to a document the first time they are
+opened and rewritten in the new format on the next save, so nothing needs
+migrating up front.
+
+### Note links and backlinks
+
+Typing `@` opens a search over notes and notebooks and inserts a `noteLink`
+node holding the target's id — so a link survives the target being renamed, and
+the label is refreshed from the current title whenever the note is opened.
+
+The server cannot read encrypted note bodies, so it cannot discover links
+itself. The client sends the ids it references alongside the content, and the
+server maintains a `note_links` index from them. That index is what powers
+`GET /api/notes/:id/backlinks` and the "Linked from N notes" bar under the
+editor.
+
+---
+
+## Full-Text Search
+
+Search runs entirely on the client. The server stores note bodies encrypted and
+deliberately keeps no plaintext index, so it cannot search them — and a
+server-side index would undo the point of encrypting at rest.
+
+Bodies are normally fetched only when a note is opened, which would leave a
+fresh device with nothing to search. After login a background pass backfills the
+missing ones into IndexedDB, slowly enough to stay out of the way, indexing each
+as it lands. Searching therefore also works offline.
+
+Matching is AND across terms, case- and diacritic-insensitive (`kuhlschrank`
+finds *Kühlschrank*), with title matches ranked above body matches. Results show
+a snippet around the first match.
+
+> Bodies of notes edited on another device are refreshed when that note is
+> opened, so search results for untouched notes can lag behind until then.
+
+---
+
+## Attachments
+
+Images used to be inlined into the note body as base64 data URIs — a few
+screenshots turned one note into megabytes that were re-encrypted and re-uploaded
+on every keystroke. They are now separate blobs; the body only keeps an id.
+
+- Stored on disk under the SHA-256 of their bytes, so the same image pasted into
+  ten notes is kept once
+- Uploads are type-checked against the actual bytes, not the declared MIME type
+- Downloads require the owner's token, so `<img>` cannot fetch them directly —
+  the client fetches with its token, caches the blob in IndexedDB and renders a
+  blob URL, which also makes images work offline
+- Files with no database row are swept up daily, one hour after last write
+
+| Method | Endpoint                | Description                        |
+|--------|-------------------------|------------------------------------|
+| POST   | `/api/attachments`      | Upload a base64 data URL           |
+| GET    | `/api/attachments/:id`  | Fetch the bytes (owner only)       |
+
+> Removing an image from a note does not yet delete its blob: the body is
+> encrypted, so the server cannot tell what is still referenced. Unused blobs
+> cost disk space, nothing else.
+
+---
+
+## Version History
+
+Every write snapshots the state it is about to replace into `note_versions`,
+encrypted the same way the note itself is.
+
+Saves arrive about once a second while typing, so snapshots **coalesce**: within
+a 5-minute window the existing newest version already represents "before this
+editing session". Two cases bypass the window, because they are exactly the ones
+worth undoing:
+
+- a write that shrinks a note to under half its size (`large-deletion`)
+- clearing a drawing (`drawing-cleared`)
+
+Restoring snapshots the current state first (`before-restore`), so picking the
+wrong version is not a one-way door. A restored body also rebuilds its entries
+in the backlink index.
+
+**Retention** — the newest 50 versions per note, trimmed on every write, plus a
+daily sweep of anything older than 90 days. Both are configurable:
+
+| Variable                   | Default | Meaning                                  |
+|----------------------------|---------|------------------------------------------|
+| `MAX_VERSIONS_PER_NOTE`    | `50`    | Versions kept per note                   |
+| `VERSION_RETENTION_DAYS`   | `90`    | Age after which a version is dropped     |
+| `VERSION_COALESCE_MINUTES` | `5`     | Window in which saves share one snapshot |
+
+**Deleting a note** — moving one to the trash keeps its history, because the
+note can still be restored. Deleting it permanently, or emptying the trash,
+removes its versions along with it (`ON DELETE CASCADE`), leaving no orphaned
+rows behind.
+
+| Method | Endpoint                                  | Description                |
+|--------|-------------------------------------------|----------------------------|
+| GET    | `/api/notes/:id/versions`                 | List (metadata only)       |
+| GET    | `/api/notes/:id/versions/:versionId`      | One version, decrypted     |
+| POST   | `/api/notes/:id/versions/:versionId/restore` | Restore it              |
+
+> Version history protects against **overwritten** data. It does not protect
+> against a lost disk, because it lives in the same database — that is what
+> backing up the data directory is for.
+
+---
+
+## Drawings
+
+Drawings are **vector strokes**, not bitmaps. Every stroke is recorded in one canonical
+page space of 1200 × 1600 units:
+
+```json
+{ "v": 1, "w": 1200, "h": 1600, "strokes": [
+  { "t": "pen", "c": "#e94560", "s": 5.5, "p": [100,100, 200,180, 300,140] }
+]}
+```
+
+`t` is the tool (`pen` | `highlighter` | `eraser`), `c` the colour, `s` the width in
+canonical units, and `p` a flat `x,y` point list. Each viewer scales that page to the
+room it has and rasterizes at its own device pixel ratio, which is what makes a note
+look the same on a phone and on a desktop — and stay crisp on both. Stroke data is
+encrypted at rest like note content.
+
+Notes drawn before this format still carry a PNG in `drawing_data_path`; it renders
+underneath any newer strokes so nothing is lost.
+
+---
+
 ## Conflict Resolution
 
 InkNote uses **vector clocks** to detect conflicts:
@@ -203,7 +435,8 @@ Wrap the React app directly in Electron for desktop. Add native file system acce
 
 | Layer     | Technology                         |
 |-----------|-------------------------------------|
-| Frontend  | React (web), adaptable to RN/Flutter |
+| Frontend  | React 18 + Vite                     |
+| Editor    | TipTap (ProseMirror)                |
 | Backend   | Node.js, Express                    |
 | Database  | SQLite (dev), PostgreSQL (prod)     |
 | Real-time | WebSocket (ws library)              |