feat(ground-suite): add local vehicle catalog

ground-suite/lib/features/fleet/domain/fleet_unit.dart

@@ -0,0 +1,46 @@
+import '../../vehicle_workspace/domain/vehicle_definition.dart';
+
+/// An operator-created fleet unit in the local planning workspace.
+///
+/// It deliberately contains no received identity, platform, authority, or
+/// physical pose. Those must arrive through separate reviewed bindings later.
+class FleetUnit {
+  const FleetUnit({
+    required this.localUnitId,
+    required this.displayName,
+    required this.definition,
+    required this.localPlacement,
+  });
+
+  final String localUnitId;
+  final String displayName;
+  final VehicleDefinition definition;
+  final LocalScenePoint localPlacement;
+
+  FleetUnit copyWith({String? displayName}) => FleetUnit(
+    localUnitId: localUnitId,
+    displayName: displayName ?? this.displayName,
+    definition: definition,
+    localPlacement: localPlacement,
+  );
+}
+
+/// A normalized placement in the operator's local tactical scene.
+///
+/// This is deliberately not a geographic position, vehicle pose, or received
+/// location. A future map binding will keep reported coordinates separate.
+class LocalScenePoint {
+  const LocalScenePoint({required this.x, required this.y})
+    : assert(x >= 0 && x <= 1),
+      assert(y >= 0 && y <= 1);
+
+  final double x;
+  final double y;
+
+  @override
+  bool operator ==(Object other) =>
+      other is LocalScenePoint && other.x == x && other.y == y;
+
+  @override
+  int get hashCode => Object.hash(x, y);
+}