feat: bookmarks and notes management

- Backend: Django REST Framework API with Bookmark and Note models
  - ViewSets with user-scoped querysets and select_related for N+1 prevention
  - Create/List/Detail/Update/Delete endpoints
  - Batch delete operations
  - Unique constraint on user+book+page for bookmarks
  - IsOwner permission class for object-level access control
  - Full serializer validation (page > 0, non-empty content, duplicate check)
  - 30+ pytest-django tests covering CRUD, auth, filtering, edge cases

- Frontend: React TypeScript components
  - AnnotationsContext with useReducer for state management
  - BookmarkList, NoteList, AddAnnotationForm, AnnotationsDashboard
  - Inline note editing with immediate save
  - Batch delete support
  - API client with JWT auto-refresh interceptors
  - Paginated query hook for infinite scroll support
  - Responsive CSS with loading/empty states

- Infrastructure: Django project with custom User model, JWT auth, CORS
  - PostgreSQL database models with proper FK and indexes
  - Django admin configuration for all models

frontend/src/components/annotations/BookmarksNotesPage.tsx

@@ -0,0 +1,23 @@
+import React from "react";
+import { AnnotationsDashboard } from "@/components/annotations";
+
+interface BookmarksNotesPageProps {
+  bookId?: string;
+}
+
+export function BookmarksNotesPage({
+  bookId,
+}: BookmarksNotesPageProps): React.ReactElement {
+  return (
+    <div className="page">
+      <h2>Bookmarks & Notes</h2>
+      <AnnotationsDashboard
+        bookId={bookId}
+        onNavigateToPage={(bookId, page) => {
+          // Navigate to the book reader page at the specific page
+          window.location.href = `/books/${bookId}?page=${page}`;
+        }}
+      />
+    </div>
+  );
+}