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/config/config.go

@@ -26,6 +26,9 @@ type Config struct {
 	DevMode      bool          // If true, allow multiple clients without auth
 
 	DatabaseURL string // Postgres connection string; required at runtime
+
+	UDPVideoAddr string // UDP address to listen on for video, e.g. ":9999"
+	ESPCmdPort   int    // Port on ESP32 that listens for commands, e.g. 8888
 }
 
 // Load reads configuration from environment variables, applying defaults.
@@ -44,6 +47,8 @@ func Load() (*Config, error) {
 		SnapshotRate: getEnvInt("X0GP_SNAPSHOT_RATE", 30),
 		DevMode:      getEnvBool("X0GP_DEV_MODE", true),
 		DatabaseURL:  getEnv("DATABASE_URL", ""),
+		UDPVideoAddr: getEnv("X0GP_UDP_VIDEO_ADDR", ":9999"),
+		ESPCmdPort:   getEnvInt("X0GP_ESP_CMD_PORT", 8888),
 	}
 
 	if c.TickRate <= 0 || c.TickRate > 240 {