Add WebRTC support and remove deviceId from apis

server/internal/control/race.go

@@ -47,6 +47,7 @@ type Car struct {
 	ID         string
 	DriverID   string // session id
 	DriverName string
+	DeviceID   *int   // internal mapping to physical ESP32 device ID
 	X, Y       float64
 	Heading    float64 // radians
 	Speed      float64 // m/s
@@ -169,7 +170,7 @@ func (e *Engine) SetPhase(p RacePhase) { e.phase.Store(int32(p)) }
 
 // AddCar registers a car and returns it. Returns an error if the driver
 // already has a car or the max car count is reached.
-func (e *Engine) AddCar(driverID, driverName string, slot int) (*Car, error) {
+func (e *Engine) AddCar(driverID, driverName string, slot int, deviceID *int) (*Car, error) {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 
@@ -185,6 +186,7 @@ func (e *Engine) AddCar(driverID, driverName string, slot int) (*Car, error) {
 		ID:         id,
 		DriverID:   driverID,
 		DriverName: driverName,
+		DeviceID:   deviceID,
 		// Spread cars along start grid (x = 0, y = slot * 0.4 m).
 		Y: float64(slot) * 0.4,
 	}