feat: implement sensor calibration flow

lib/data/repositories/phoenix_sensor_repository.dart

@@ -59,4 +59,36 @@ class PhoenixSensorRepository implements SensorRepository {
   Stream<Map<String, dynamic>> sensorEvents() => realtime
       .channelMessages('sensors')
       .map((m) => {'event': m.event, ...m.payload});
+
+  @override
+  Future<int> beginCalibration(int id) async {
+    final json = await client.beginCalibration(id);
+    return json['samples_needed'] as int;
+  }
+
+  @override
+  Future<void> startStage(int id, double distance) =>
+      client.startStage(id, distance);
+
+  @override
+  Future<({double rssiRef, double pathLossExp})> finishCalibration(
+      int id) async {
+    final json = await client.finishCalibration(id);
+    return (
+      rssiRef: (json['rssi_ref'] as num).toDouble(),
+      pathLossExp: (json['path_loss_exp'] as num).toDouble(),
+    );
+  }
+
+  @override
+  Future<void> cancelCalibration(int id) => client.cancelCalibration(id);
+
+  @override
+  Stream<({String event, Map<String, dynamic> payload})> calibrationEvents(
+          String sensorDeviceId) =>
+      realtime.channelMessages('calibration:$sensorDeviceId');
+
+  @override
+  void leaveCalibrationChannel(String sensorDeviceId) =>
+      realtime.leaveChannel('calibration:$sensorDeviceId');
 }