Integrate React Query for data management and enhance Debug Preferences

- Added React Query for managing API calls related to assistants and voices.
- Introduced `useAssistantsQuery` and `useVoicesQuery` hooks for fetching data.
- Implemented mutations for creating, updating, and deleting voices using React Query.
- Integrated a global `QueryClient` for managing query states and configurations.
- Refactored components to utilize the new query hooks, improving data handling and performance.
- Added a Zustand store for managing debug preferences, including WebSocket URL and audio settings.

web/package.json

@@ -9,7 +9,9 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@tanstack/react-query": "^5.90.2",
     "lucide-react": "^0.563.0",
+    "zustand": "^5.0.8",
     "react-router-dom": "^7.13.0",
     "@google/genai": "^1.39.0",
     "react": "^19.2.4",