feat(aether): initial commit – self-hosted Cloud, Phasen 1–7

Go-Backend (chi, pgx, golang-migrate) + React/TS-Frontend als PWA.
Enthalten: Auth inkl. OIDC, Dateien mit Versionen und Papierkorb,
Freigaben (Links + intern), WebDAV, Gruppenordner, Admin/Theming,
Volltextsuche mit OCR, eigener PDF-Betrachter und WOPI-Office
(Collabora/OnlyOffice).

Nicht im Repo: deploy/.env (Sitzungsschlüssel, DB- und Admin-Passwort)
sowie alle Daten- und Build-Verzeichnisse – siehe .gitignore.

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

backend/pkg/db/migrations/000001_init.up.sql

@@ -0,0 +1,103 @@
+-- Aether – Initial schema
+-- Phase 0: users, sessions, folders, files (no email)
+
+CREATE EXTENSION IF NOT EXISTS "pgcrypto";
+
+-- ── Users ─────────────────────────────────────────────────────────────────────
+CREATE TABLE users (
+    id          UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    username    TEXT        NOT NULL UNIQUE,
+    password    TEXT        NOT NULL,       -- Argon2id hash
+    is_admin    BOOLEAN     NOT NULL DEFAULT FALSE,
+    quota_bytes BIGINT      NOT NULL DEFAULT 10737418240, -- 10 GB default
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- ── Sessions ──────────────────────────────────────────────────────────────────
+CREATE TABLE sessions (
+    id         TEXT        PRIMARY KEY,
+    user_id    UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    data       BYTEA       NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    expires_at TIMESTAMPTZ NOT NULL
+);
+
+CREATE INDEX idx_sessions_user_id  ON sessions(user_id);
+CREATE INDEX idx_sessions_expires  ON sessions(expires_at);
+
+-- ── Folders ───────────────────────────────────────────────────────────────────
+CREATE TABLE folders (
+    id         UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    owner_id   UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    parent_id  UUID        REFERENCES folders(id) ON DELETE CASCADE,
+    name       TEXT        NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (owner_id, parent_id, name)
+);
+
+CREATE INDEX idx_folders_owner   ON folders(owner_id);
+CREATE INDEX idx_folders_parent  ON folders(parent_id);
+
+-- ── Files ─────────────────────────────────────────────────────────────────────
+CREATE TABLE files (
+    id           UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    owner_id     UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    folder_id    UUID        REFERENCES folders(id) ON DELETE CASCADE,
+    name         TEXT        NOT NULL,
+    mime_type    TEXT        NOT NULL DEFAULT 'application/octet-stream',
+    size         BIGINT      NOT NULL DEFAULT 0,
+    checksum     TEXT        NOT NULL,   -- SHA-256 hex
+    storage_key  TEXT        NOT NULL,   -- path within blob storage
+    version      INTEGER     NOT NULL DEFAULT 1,
+    is_deleted   BOOLEAN     NOT NULL DEFAULT FALSE,
+    deleted_at   TIMESTAMPTZ,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_files_owner     ON files(owner_id);
+CREATE INDEX idx_files_folder    ON files(folder_id);
+CREATE INDEX idx_files_deleted   ON files(is_deleted);
+CREATE INDEX idx_files_storage   ON files(storage_key);
+
+-- Partial unique index: no two non-deleted files can share name+folder for the same owner.
+CREATE UNIQUE INDEX idx_files_unique_name
+    ON files(owner_id, folder_id, name)
+    WHERE NOT is_deleted;
+
+-- ── File versions ─────────────────────────────────────────────────────────────
+-- Previous versions of files (kept for Soft-Delete + versioning).
+CREATE TABLE file_versions (
+    id           UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    file_id      UUID        NOT NULL REFERENCES files(id) ON DELETE CASCADE,
+    version      INTEGER     NOT NULL,
+    size         BIGINT      NOT NULL,
+    checksum     TEXT        NOT NULL,
+    storage_key  TEXT        NOT NULL,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_file_versions_file ON file_versions(file_id);
+
+-- ── Updated_at trigger ────────────────────────────────────────────────────────
+CREATE OR REPLACE FUNCTION update_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = NOW();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER trg_users_updated_at
+    BEFORE UPDATE ON users
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER trg_folders_updated_at
+    BEFORE UPDATE ON folders
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER trg_files_updated_at
+    BEFORE UPDATE ON files
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();