Set the note left, count its pages, choose its typeface, align its text

The column sat in the middle, so it moved as the window was resized and the
start of every line landed somewhere new. It is against the margin now.

The toolbar counts pages in the words the PDF reader uses, with a hairline where
each ends. Pages are drawn, never stored: the note stays one document, Markdown
has no page, and a check asserts none reaches the stored body. The current page
is the one under the middle of the window — measuring from the top claimed "page
1" while you stood at the foot of a two-page note, because a window is shorter
than a page.

The typeface is a per-account setting rather than a per-browser one, because a
choice about how your own notes are set should follow you to the phone. The
server takes serif, sans or mono and drops anything else; that column is written
by a browser, so it is an input like any other.

Alignment is a small extension of our own — one attribute, a parse rule, a render
rule — so the schema every stored note is validated against stays in files this
project owns. Markdown has no alignment: what CommonMark allows is embedded HTML,
so non-left blocks travel as `<div align="…">`, the one form most readers still
honour, and the importer puts it back on the paragraphs. Left is never written.

The full run caught a crash I had put in: PdfWorkspace used `noteFont` without
taking it as a prop, which the build cannot see and the type checker does not
reach in .jsx. It killed the notes panel beside a PDF, and `offline` failed with
it because the whole app was broken.

224 unit tests, 263 browser checks across twelve suites.

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

backend/server.js

@@ -269,13 +269,31 @@ function normalizeUsername(raw) {
 }
 
 /** The fields of a user row that may leave the server. Never the password hash. */
+/** What a client is allowed to know about a user. */
 const publicUser = (row) => ({
   id: row.id,
   username: row.username,
   displayName: row.display_name,
   isAdmin: !!row.is_admin,
+  preferences: readPreferences(row.preferences),
 });
 
+/* Interface settings the client may store. Anything else is dropped rather than
+ * kept: this column is written by the browser, so it is an input like any other,
+ * and a fixed shape is what stops it becoming a place to put arbitrary data. */
+const NOTE_FONTS = ["serif", "sans", "mono"];
+
+function readPreferences(raw) {
+  let parsed = null;
+  try {
+    parsed = raw ? JSON.parse(raw) : null;
+  } catch {
+    parsed = null;
+  }
+  const font = parsed?.noteFont;
+  return { noteFont: NOTE_FONTS.includes(font) ? font : "serif" };
+}
+
 // 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() {
@@ -364,6 +382,15 @@ if (!tableColumns("users").includes("is_admin")) {
   db.exec("ALTER TABLE users ADD COLUMN is_admin INTEGER NOT NULL DEFAULT 0");
 }
 
+/* Per-account interface settings, as JSON.
+ *
+ * On the account rather than in the browser's storage: a choice about how your
+ * own notes are set should follow you to the phone, not be made again on every
+ * device. Only presentation lives here — nothing the server acts on. */
+if (!tableColumns("users").includes("preferences")) {
+  db.exec("ALTER TABLE users ADD COLUMN preferences TEXT");
+}
+
 /**
  * Makes sure exactly one way in exists.
  *
@@ -624,6 +651,20 @@ app.put("/api/auth/profile", authMiddleware, (req, res) => {
   res.json(publicUser(db.prepare("SELECT * FROM users WHERE id = ?").get(req.userId)));
 });
 
+app.put("/api/auth/preferences", authMiddleware, (req, res) => {
+  const { noteFont } = req.body || {};
+  if (noteFont !== undefined && !NOTE_FONTS.includes(noteFont)) {
+    return res.status(400).json({ error: `noteFont must be one of ${NOTE_FONTS.join(", ")}` });
+  }
+  const current = readPreferences(
+    db.prepare("SELECT preferences FROM users WHERE id = ?").get(req.userId)?.preferences
+  );
+  const next = { ...current, ...(noteFont !== undefined ? { noteFont } : {}) };
+  db.prepare("UPDATE users SET preferences = ?, updated_at = datetime('now') WHERE id = ?")
+    .run(JSON.stringify(next), req.userId);
+  res.json(publicUser(db.prepare("SELECT * FROM users WHERE id = ?").get(req.userId)));
+});
+
 app.put("/api/auth/username", authMiddleware, async (req, res, next) => {
   try {
   const { newUsername, password } = req.body;