fix(reader): stabilize chrome panels, bookmarks end-to-end, dead UI removal

Phase 0 of the reader redesign:

- Panels no longer render under the top/bottom bars: sidebars get
  measured insets (same resize/safe-area mechanism as the viewport);
  panel max-height now derives from the bounded sidebar instead of a
  100vh guess; right-side border targets the actual sidebar.
- Bookmarks work end-to-end for the first time: REST CRUD under
  /api/media-items/:id/bookmarks (create/delete route through
  AnnotationService for dedup/LWW/tombstones), fix UpdateMediaBookmark
  referencing nonexistent updated_at column, frontend posts to the
  real API with per-format position (CFI vs page), live list with
  jump + delete instead of SSR-only snapshot.
- Fix chapter matching in progress saves: boundaries were compared by
  a nonexistent tocItem property, so chapter was never persisted.
- Remove dead UI: Navigator panel stub, empty dictionary popup shell,
  unwired Chrome Behavior select; purge 160 stale build artifacts.
- Reader chrome now follows the user's app theme instead of hardcoded
  theme-tokyo-night.

internal/router/media.go

@@ -41,6 +41,12 @@ func registerMediaRoutes(cfg *Config) {
 	protected.PUT("/media-items/:id/highlights/:highlightId", cfg.MediaHandler.UpdateMediaHighlight)
 	protected.DELETE("/media-items/:id/highlights/:highlightId", cfg.MediaHandler.DeleteMediaHighlight)
 
+	// Bookmark routes (all authenticated users)
+	protected.GET("/media-items/:id/bookmarks", cfg.MediaHandler.GetMediaBookmarks)
+	protected.POST("/media-items/:id/bookmarks", cfg.MediaHandler.CreateMediaBookmark)
+	protected.PUT("/media-items/:id/bookmarks/:bookmarkId", cfg.MediaHandler.UpdateMediaBookmark)
+	protected.DELETE("/media-items/:id/bookmarks/:bookmarkId", cfg.MediaHandler.DeleteMediaBookmark)
+
 	// Admin-only media routes
 	admin.POST("/media-items", cfg.MediaHandler.CreateMediaItem)
 	admin.PUT("/media-items/:id", cfg.MediaHandler.UpdateMediaItem)