feat(server): integrate UDP video service and normalize database schema

- Implement UDPVideoService to stream MJPEG video frames from ESP32s via UDP and send control commands.
- Normalize race database schema:
  - Remove redundant driver_ids array from races table (migration 011).
  - Move per-driver outcomes (total_time_ms, best_lap_ms, position) to race_drivers table (migration 012).
  - Add device_id column to lobby_drivers to link active physical devices (migration 013).
- Update WebSocket handler to pass lobbySvc, driversSvc, and videoSvc for driver identity tracking, syncing in-memory driver metadata, and forwarding WS controls to physical cars.
- Add CORS middleware to HTTP routes.
- Regenerate Swagger documentation.

server/internal/transport/codec.go

@@ -241,6 +241,7 @@ type LobbyDriver struct {
 	LastSeenMs  int64  `json:"last_seen_ms"`
 	Country     string `json:"country,omitempty"`
 	AvatarHue   int    `json:"avatar_hue,omitempty"`
+	DeviceID    *int   `json:"device_id,omitempty"`
 }
 
 // LobbySnapshot is the full lobby state, broadcast on change.