Address Reid's PR #25 review comments

🔴 Blocking fixes:
- Add reader app migration (apps/reader/migrations/0001_initial.py)
- Remove duplicate ReadingSettings from apps.books to resolve model clash
  with apps.reader.ReadingSettings (keep richer reader version)
- Redirect books serializers/views to use reader app's ReadingSettings
- Update frontend API endpoints to match main's backend routes:
  /api/books/ebooks/{id}/toc/ (chapters)
  /api/books/ebooks/{id}/content/?page=N (chapter content)
  /api/books/ebooks/{id}/progress/ (GET/PATCH progress)
- Add DOMPurify sanitization for dangerouslySetInnerHTML (XSS fix)

🟡 Non-blocking fixes:
- Fix CSS typo: landascape -> landscape in reader.css
- Add null-safe fallback for book.title in ReadingPage

frontend/package.json

@@ -11,20 +11,21 @@
     "lint": "eslint ."
   },
   "dependencies": {
+    "axios": "^1.7.9",
+    "dompurify": "^3.4.7",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
-    "react-router-dom": "^7.1.0",
-    "axios": "^1.7.9"
+    "react-router-dom": "^7.1.0"
   },
   "devDependencies": {
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.2.0",
     "@types/react": "^19.0.0",
     "@types/react-dom": "^19.0.0",
     "@vitejs/plugin-react": "^4.3.4",
+    "jsdom": "^25.0.0",
     "typescript": "~5.7.0",
     "vite": "^6.0.0",
-    "vitest": "^2.1.0",
-    "@testing-library/react": "^16.2.0",
-    "@testing-library/jest-dom": "^6.6.3",
-    "jsdom": "^25.0.0"
+    "vitest": "^2.1.0"
   }
-}
+}