feat(ground-suite): add replay observability console

ground-suite/lib/core/transport/replay_vehicle_data_port.dart

@@ -0,0 +1,65 @@
+import '../observations/observed_event.dart';
+import '../observations/vehicle_data_port.dart';
+import '../observations/vehicle_data_update.dart';
+
+/// Deterministic observations for the first Ground Suite workflow.
+///
+/// This is intentionally a typed replay rather than a pretend connected
+/// vehicle. Raw frame replay moves behind the MAVLink decoder once bindings
+/// are generated from the MAVLink Common and Kaptan dialect definitions.
+final class ReplayVehicleDataPort implements VehicleDataPort {
+  const ReplayVehicleDataPort();
+
+  @override
+  String get label => 'Replay fixture';
+
+  @override
+  bool get isReplay => true;
+
+  @override
+  Stream<VehicleDataUpdate> observe() => Stream<VehicleDataUpdate>.fromIterable(
+    _events.map(ObservationReceived.new),
+  );
+
+  @override
+  Future<void> close() async {}
+
+  static final List<ObservedEvent> _events = [
+    HeartbeatEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12),
+      systemId: 1,
+      componentId: 1,
+      armed: false,
+      vehicleState: 'Standby',
+    ),
+    TelemetryEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 1),
+      kind: TelemetryKind.rawImu,
+    ),
+    TelemetryEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 2),
+      kind: TelemetryKind.distanceSensor,
+    ),
+    LogEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 3),
+      level: MavSeverity.warning,
+      message: 'Range aid stale',
+      flags: LogEvent.coalescedFlag,
+    ),
+    ErrorEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 4),
+      path: 'kaptan_drivers::lidar_lite_v3::error::Error::TransferFault',
+      additionalInformation: 'The replay contains a bounded error detail.',
+      flags: ErrorEvent.truncatedFlag,
+    ),
+    LogEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 5),
+      level: MavSeverity.info,
+      message: 'Replay fixture complete',
+    ),
+    ShutdownEvent(
+      receivedAt: DateTime.utc(2026, 8, 10, 12, 0, 6),
+      reason: KaptanShutdownReason.operator,
+    ),
+  ];
+}