delete CloudKit and added BalanceFlutter

BalanceFlutter/test/runtime_lock_test.dart

@@ -0,0 +1,48 @@
+import 'package:balance_flutter/services/runtime_lock.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  const channel = MethodChannel('balance/runtime');
+  final messenger =
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
+  tearDown(() {
+    messenger.setMockMethodCallHandler(channel, null);
+    debugDefaultTargetPlatformOverride = null;
+  });
+
+  test('Android release carries the acquired engine token', () async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    final calls = <MethodCall>[];
+    messenger.setMockMethodCallHandler(channel, (call) async {
+      calls.add(call);
+      return call.method == 'acquireLock' ? 'owner-token' : null;
+    });
+    final lock = RuntimeLock();
+    await lock.acquire();
+    await expectLater(lock.acquire(), throwsStateError);
+    await lock.release();
+    expect(calls.map((call) => call.method), ['acquireLock', 'releaseLock']);
+    expect(calls.last.arguments, {'token': 'owner-token'});
+    await expectLater(lock.release(), throwsStateError);
+  });
+
+  test('missing native ownership token fails closed', () async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    messenger.setMockMethodCallHandler(channel, (_) async => null);
+    await expectLater(RuntimeLock().acquire(), throwsStateError);
+  });
+
+  test('non-Android platforms never invoke the native lock channel', () async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.linux;
+    messenger.setMockMethodCallHandler(
+      channel,
+      (_) async => fail('Unexpected native channel call'),
+    );
+    final lock = RuntimeLock();
+    await lock.acquire();
+    await lock.release();
+  });
+}