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.

web/static/input.css

@@ -754,10 +754,11 @@
     background-color: var(--bg-secondary);
     border-right: 1px solid var(--border);
     width: 320px;
-    max-height: calc(100vh - 8rem);
+    max-width: calc(100vw - 1rem);
+    max-height: 100%;
     overflow-y: auto;
   }
-  .panel-container[data-side="right"] {
+  #right-sidebar .panel-container {
     border-right: none;
     border-left: 1px solid var(--border);
   }