feat(reward): 新增客户端奖励中心

lib/core/data/services/google_auth_service.dart

@@ -1,5 +1,6 @@
 // Author: fruit.com.cn
 
+import 'dart:async';
 import 'dart:io' show Platform;
 
 import 'package:flutter/foundation.dart';
@@ -58,6 +59,10 @@ class GoogleAuthService {
   static const String _serverClientId =
       '11115008580-dbqe47fhp5560nhrocrppiq7hcnlvl1s.apps.googleusercontent.com';
 
+  /// 授权等待上限：插件在账号被撤销后可能永不返回，必须有超时兜底，
+  /// 否则页面 loading 状态会一直卡住、按钮再也点不动。
+  static const Duration _authTimeout = Duration(seconds: 60);
+
   final GoogleSignIn _signIn;
   bool _initialized = false;
 
@@ -68,22 +73,41 @@ class GoogleAuthService {
       if (!_signIn.supportsAuthenticate()) {
         return const GoogleSignInOutcome.unavailable();
       }
-      final account = await _signIn.authenticate();
+      // 先清掉插件缓存的旧账号：用户可能在 Google 侧撤销过授权或切换过账号，
+      // 残留状态会让 authenticate 直接返回失效账号或干脆不弹授权页。
+      await _clearStaleAccount();
+      final account = await _signIn.authenticate().timeout(_authTimeout);
       final idToken = account.authentication.idToken;
       if (idToken == null || idToken.isEmpty) {
         return const GoogleSignInOutcome.failed();
       }
       return GoogleSignInOutcome.success(idToken);
+    } on TimeoutException {
+      await _clearStaleAccount();
+      return const GoogleSignInOutcome.failed();
     } on GoogleSignInException catch (error) {
       if (error.code == GoogleSignInExceptionCode.canceled) {
         return const GoogleSignInOutcome.canceled();
       }
+      // 失败多半是插件缓存了已失效的账号（用户手动撤销授权、换账号），
+      // 清掉本地状态，下次点击才能重新拉起授权页。
+      await _clearStaleAccount();
       return const GoogleSignInOutcome.failed();
     } catch (_) {
+      await _clearStaleAccount();
       return const GoogleSignInOutcome.failed();
     }
   }
 
+  /// 清掉插件缓存的 Google 账号；失败不影响登录结果，异常直接吞掉。
+  Future<void> _clearStaleAccount() async {
+    try {
+      await _signIn.signOut();
+    } catch (_) {
+      // 忽略：清缓存失败不应阻断页面恢复
+    }
+  }
+
   /// 插件要求先 initialize 才能 authenticate；只做一次。
   Future<void> _ensureInitialized() async {
     if (_initialized) return;

lib/core/data/services/reward_controller.dart

@@ -0,0 +1,108 @@
+// Author: fruit.com.cn
+
+import 'package:flutter/foundation.dart';
+
+import '../models/reward.dart';
+import '../remote/api_exception.dart';
+import '../repositories/reward_repository.dart';
+
+/// 奖励中心状态与签到、领取动作。
+class RewardController extends ChangeNotifier {
+  RewardController(this._repository);
+
+  final RewardRepository _repository;
+  RewardOverview? overview;
+  bool loading = false;
+  bool checkingIn = false;
+  String? claimingTaskId;
+  String? error;
+  String? actionError;
+  bool _disposed = false;
+  String _locale = 'id';
+
+  Future<void> load(String locale) async {
+    if (_disposed || loading) return;
+    _locale = locale;
+    loading = true;
+    error = null;
+    _notify();
+    try {
+      overview = await _repository.fetchOverview(locale);
+    } on ApiException catch (exception) {
+      error = exception.message;
+    } catch (_) {
+      error = 'rewardLoadFailed';
+    } finally {
+      loading = false;
+      _notify();
+    }
+  }
+
+  /// 签到成功后刷新总览，确保签到格和余额来自服务端事实。
+  Future<RewardActionResult?> checkIn() async {
+    if (_disposed || checkingIn) return null;
+    checkingIn = true;
+    actionError = null;
+    _notify();
+    try {
+      final result = await _repository.checkIn();
+      await _reload();
+      return result;
+    } on ApiException catch (exception) {
+      actionError = exception.message;
+      return null;
+    } catch (_) {
+      actionError = 'rewardActionFailed';
+      return null;
+    } finally {
+      checkingIn = false;
+      _notify();
+    }
+  }
+
+  /// 领取任务奖励；同一时刻只允许一个领取动作。
+  Future<RewardActionResult?> claim(String taskId) async {
+    if (_disposed || claimingTaskId != null) return null;
+    claimingTaskId = taskId;
+    actionError = null;
+    _notify();
+    try {
+      final result = await _repository.claim(taskId);
+      await _reload();
+      return result;
+    } on ApiException catch (exception) {
+      actionError = exception.message;
+      return null;
+    } catch (_) {
+      actionError = 'rewardActionFailed';
+      return null;
+    } finally {
+      claimingTaskId = null;
+      _notify();
+    }
+  }
+
+  void reset() {
+    overview = null;
+    loading = false;
+    checkingIn = false;
+    claimingTaskId = null;
+    error = null;
+    actionError = null;
+    _notify();
+  }
+
+  Future<void> _reload() async {
+    overview = await _repository.fetchOverview(_locale);
+  }
+
+  void _notify() {
+    if (!_disposed) notifyListeners();
+  }
+
+  @override
+  void dispose() {
+    _disposed = true;
+    super.dispose();
+  }
+}