feat: add level schema and tilemap tests

- Introduced a JSON schema for game levels to validate level data structure.
- Added comprehensive tests for tilemap functionalities including collision resolution, tile type retrieval, and level loading.
- Enhanced the SyncSystem to manage remote state synchronization and interpolation for smoother gameplay.
- Implemented an AudioSystem with tests to ensure audio loading and playback functionality.
- Updated NetworkClient to support dynamic WebSocket URLs from environment variables.
- Added integration tests for matchmaking and network communication between clients.
- Improved RenderSystem to correctly render player nicknames above sprites.

Co-authored-by: Copilot <copilot@github.com>

package.json

@@ -11,9 +11,10 @@
     "test:watch": "vitest"
   },
   "devDependencies": {
+    "@types/ws": "^8.18.1",
+    "jsdom": "^24.1.0",
     "typescript": "~6.0.2",
     "vite": "^8.0.10",
-    "vitest": "^1.6.0",
-    "jsdom": "^24.1.0"
+    "vitest": "^1.6.0"
   }
 }