feat(bookmarks): api+store — per-user CRUD, owner-scoped 404, percent-ordered list

backend/internal/db/schema.sql

@@ -19,3 +19,11 @@ CREATE TABLE IF NOT EXISTS reading_progress (
   locator JSONB NOT NULL DEFAULT '{}', percent DOUBLE PRECISION NOT NULL DEFAULT 0,
   updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
   PRIMARY KEY (user_id, library_id, book_path));
+CREATE TABLE IF NOT EXISTS bookmarks (
+  id BIGSERIAL PRIMARY KEY,
+  user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  library_id BIGINT NOT NULL, book_path TEXT NOT NULL,
+  locator JSONB NOT NULL, percent DOUBLE PRECISION NOT NULL DEFAULT 0,
+  note TEXT NOT NULL DEFAULT '',
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now());
+CREATE INDEX IF NOT EXISTS bookmarks_user_book_idx ON bookmarks (user_id, library_id, book_path);

backend/internal/store/store.go

@@ -314,6 +314,57 @@ func (s *Store) ListProgress(ctx context.Context, userID int64) ([]Progress, err
 	return out, rows.Err()
 }
 
+// ---------- bookmarks ----------
+
+type Bookmark struct {
+	ID        int64
+	LibraryID int64
+	BookPath  string
+	Locator   []byte
+	Percent   float64
+	Note      string
+	CreatedAt time.Time
+}
+
+func (s *Store) InsertBookmark(ctx context.Context, userID, libID int64, bookPath string, locator []byte, percent float64, note string) (int64, error) {
+	var id int64
+	err := s.P.QueryRow(ctx,
+		`INSERT INTO bookmarks (user_id, library_id, book_path, locator, percent, note)
+		 VALUES ($1,$2,$3,$4,$5,$6) RETURNING id`,
+		userID, libID, bookPath, locator, percent, note).Scan(&id)
+	return id, err
+}
+
+func (s *Store) ListBookmarks(ctx context.Context, userID, libID int64, bookPath string) ([]Bookmark, error) {
+	rows, err := s.P.Query(ctx,
+		`SELECT id, library_id, book_path, locator, percent, note, created_at
+		 FROM bookmarks WHERE user_id=$1 AND library_id=$2 AND book_path=$3
+		 ORDER BY percent ASC, id ASC`, userID, libID, bookPath)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Bookmark
+	for rows.Next() {
+		var b Bookmark
+		if err := rows.Scan(&b.ID, &b.LibraryID, &b.BookPath, &b.Locator, &b.Percent, &b.Note, &b.CreatedAt); err != nil {
+			return nil, err
+		}
+		out = append(out, b)
+	}
+	return out, rows.Err()
+}
+
+func (s *Store) UpdateBookmarkNote(ctx context.Context, userID, id int64, note string) (bool, error) {
+	res, err := s.P.Exec(ctx, `UPDATE bookmarks SET note=$3 WHERE id=$1 AND user_id=$2`, id, userID, note)
+	return res.RowsAffected() > 0, err
+}
+
+func (s *Store) DeleteBookmark(ctx context.Context, userID, id int64) (bool, error) {
+	res, err := s.P.Exec(ctx, `DELETE FROM bookmarks WHERE id=$1 AND user_id=$2`, id, userID)
+	return res.RowsAffected() > 0, err
+}
+
 func (s *Store) GetProgress(ctx context.Context, userID, libID int64, bookPath string) (Progress, error) {
 	var pr Progress
 	err := s.P.QueryRow(ctx,