feat(test): Week 3 质量保障体系 — 55 新增测试 + CI/CD 流水线

前端第二批测试 (42 用例):
- AuthBloc: 16 用例 (启动恢复/登录/注册/角色选择/班级码/登出)
- HomeBloc: 8 用例 (数据加载/今日检测/心情统计/连续天数/离线容错)
- CalendarBloc: 10 用例 (月份切换/日期选择/视图模式/状态保持)
- MoodBloc: 8 用例 (统计加载/周期切换/API解析/错误处理)

后端 P0 单元测试 (13 用例):
- journal_service: 5 用例 (model_to_resp 转换/mood回退/weather回退/tags解析)
- sync_service: 8 用例 (冲突收集/DTO构造/序列化roundtrip/非冲突排除)

CI/CD:
- pr-check.yml: PR 触发 cargo fmt+check+clippy+test + flutter analyze+test
- main-merge.yml: main push 触发完整检查 + cargo audit 安全审计

测试统计: 前端 84 通过, 后端 73 通过 (全部通过)

app/test/features/calendar/bloc/calendar_bloc_test.dart

@@ -0,0 +1,230 @@
+// CalendarBloc 单元测试
+//
+// 覆盖：月份切换加载、日期选择、视图模式切换、状态保持
+// 使用 InMemoryJournalRepository 作为测试替身
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nuanji_app/data/models/journal_element.dart';
+import 'package:nuanji_app/data/models/journal_entry.dart';
+import 'package:nuanji_app/data/repositories/journal_repository.dart';
+import 'package:nuanji_app/features/calendar/bloc/calendar_bloc.dart';
+
+void main() {
+  group('CalendarBloc', () {
+    late CalendarBloc bloc;
+    late InMemoryJournalRepository repo;
+
+    setUp(() {
+      repo = InMemoryJournalRepository();
+      bloc = CalendarBloc(journalRepository: repo);
+    });
+
+    tearDown(() {
+      bloc.close();
+    });
+
+    // ===== 辅助 =====
+
+    /// 收集事件触发后的最终状态
+    Future<CalendarState> dispatch(CalendarEvent event) async {
+      bloc.add(event);
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+      return bloc.state;
+    }
+
+    /// 创建测试日记条目
+    ///
+    /// 日期放在月份中间（15 号），避免 InMemoryJournalRepository
+    /// 使用 isAfter/isBefore（严格大于/小于）时的边界问题。
+    JournalEntry _makeEntry({required String id, required DateTime date}) {
+      return JournalEntry(
+        id: id,
+        authorId: 'user-1',
+        title: '日记',
+        date: date,
+        createdAt: date,
+        updatedAt: date,
+      );
+    }
+
+    // ===== 初始状态 =====
+
+    test('初始状态为 CalendarInitial', () {
+      expect(bloc.state, isA<CalendarInitial>());
+    });
+
+    // ===== 月份切换 =====
+
+    test('CalendarMonthChanged 成功加载日记 → journalsByDate 包含数据', () async {
+      // 在 6 月 15 日创建日记
+      final june15 = DateTime(2026, 6, 15);
+      await repo.createJournal(_makeEntry(id: 'j-1', date: june15));
+
+      final state = await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+
+      expect(state, isA<CalendarLoaded>());
+      final loaded = state as CalendarLoaded;
+      expect(loaded.focusedMonth, DateTime(2026, 6, 1));
+      expect(loaded.isLoading, isFalse);
+      expect(loaded.journalsByDate, isNotEmpty);
+
+      final key = DateTime(2026, 6, 15);
+      expect(loaded.journalsByDate[key], isNotNull);
+      expect(loaded.journalsByDate[key]!.length, 1);
+      expect(loaded.journalsByDate[key]!.first.id, 'j-1');
+    });
+
+    test('CalendarMonthChanged 失败 → isLoading: false，保留旧数据', () async {
+      // 使用一个会抛异常的仓库替身
+      final failingRepo = _FailingJournalRepository();
+      final failingBloc = CalendarBloc(journalRepository: failingRepo);
+
+      // 先加载一次成功数据（这里直接 emit 一个 loaded 状态）
+      failingBloc.add(CalendarMonthChanged(DateTime(2026, 6, 1)));
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+
+      // 此时状态应为 CalendarLoaded（isLoading: false，因为加载失败）
+      expect(failingBloc.state, isA<CalendarLoaded>());
+      final loaded = failingBloc.state as CalendarLoaded;
+      expect(loaded.isLoading, isFalse);
+      expect(loaded.journalsByDate, isEmpty);
+
+      await failingBloc.close();
+    });
+
+    test('CalendarMonthChanged 保留上一个 viewMode', () async {
+      // 先加载月份，进入 CalendarLoaded 状态
+      await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+      expect(bloc.state, isA<CalendarLoaded>());
+
+      // 切换视图模式为 week
+      await dispatch(CalendarViewModeChanged(CalendarViewMode.week));
+      expect((bloc.state as CalendarLoaded).viewMode, CalendarViewMode.week);
+
+      // 再切换月份，viewMode 应该保留为 week
+      final state = await dispatch(CalendarMonthChanged(DateTime(2026, 7, 1)));
+      final loaded = state as CalendarLoaded;
+      expect(loaded.viewMode, CalendarViewMode.week);
+      expect(loaded.focusedMonth, DateTime(2026, 7, 1));
+    });
+
+    // ===== 日期选择 =====
+
+    test('CalendarDaySelected 有日记 → selectedDayJournals 不为空', () async {
+      final june15 = DateTime(2026, 6, 15);
+      await repo.createJournal(_makeEntry(id: 'j-1', date: june15));
+
+      // 先加载月份
+      await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+
+      // 选择 6 月 15 日
+      final state = await dispatch(CalendarDaySelected(june15));
+      final loaded = state as CalendarLoaded;
+      expect(loaded.selectedDay, june15);
+      expect(loaded.selectedDayJournals, isNotEmpty);
+      expect(loaded.selectedDayJournals.length, 1);
+      expect(loaded.selectedDayJournals.first.id, 'j-1');
+    });
+
+    test('CalendarDaySelected 无日记 → selectedDayJournals 为空', () async {
+      // 先加载月份（空数据）
+      await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+
+      // 选择 6 月 10 日（无日记）
+      final june10 = DateTime(2026, 6, 10);
+      final state = await dispatch(CalendarDaySelected(june10));
+      final loaded = state as CalendarLoaded;
+      expect(loaded.selectedDay, june10);
+      expect(loaded.selectedDayJournals, isEmpty);
+    });
+
+    test('CalendarDaySelected 在 CalendarInitial 状态不改变状态', () async {
+      // 不先加载月份，初始状态为 CalendarInitial
+      expect(bloc.state, isA<CalendarInitial>());
+
+      final state = await dispatch(CalendarDaySelected(DateTime(2026, 6, 15)));
+      // 状态应保持为 CalendarInitial
+      expect(state, isA<CalendarInitial>());
+    });
+
+    // ===== 视图模式 =====
+
+    test('CalendarViewModeChanged 更新 viewMode', () async {
+      // 先进入 CalendarLoaded 状态
+      await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+
+      final state = await dispatch(CalendarViewModeChanged(CalendarViewMode.timeline));
+      final loaded = state as CalendarLoaded;
+      expect(loaded.viewMode, CalendarViewMode.timeline);
+    });
+
+    test('CalendarViewModeChanged 在 CalendarInitial 状态不改变状态', () async {
+      expect(bloc.state, isA<CalendarInitial>());
+
+      final state = await dispatch(CalendarViewModeChanged(CalendarViewMode.week));
+      // 状态应保持为 CalendarInitial
+      expect(state, isA<CalendarInitial>());
+    });
+
+    // ===== 日期键归一化 =====
+
+    test('CalendarMonthChanged 日期键归一化 — 同一天不同时间映射到同一个 key', () async {
+      // 创建两篇日记，日期都是 6 月 15 日但时间不同
+      final june15Morning = DateTime(2026, 6, 15, 8, 30);
+      final june15Afternoon = DateTime(2026, 6, 15, 14, 45);
+      await repo.createJournal(_makeEntry(id: 'j-1', date: june15Morning));
+      await repo.createJournal(_makeEntry(id: 'j-2', date: june15Afternoon));
+
+      final state = await dispatch(CalendarMonthChanged(DateTime(2026, 6, 1)));
+      final loaded = state as CalendarLoaded;
+
+      // 归一化后的 key 应为 DateTime(2026, 6, 15)
+      final normalizedKey = DateTime(2026, 6, 15);
+      expect(loaded.journalsByDate.containsKey(normalizedKey), isTrue);
+      // 两篇日记都映射到同一个 key
+      expect(loaded.journalsByDate[normalizedKey]!.length, 2);
+      expect(
+        loaded.journalsByDate[normalizedKey]!.map((j) => j.id).toList()
+          ..sort(),
+        ['j-1', 'j-2'],
+      );
+    });
+  });
+}
+
+/// 加载日记时总是抛异常的仓库 — 用于测试错误路径
+class _FailingJournalRepository implements JournalRepository {
+  @override
+  Future<List<JournalEntry>> getJournals({
+    DateTime? dateFrom,
+    DateTime? dateTo,
+    int? page,
+    int? pageSize,
+  }) async {
+    throw Exception('模拟网络错误');
+  }
+
+  @override
+  Future<JournalEntry?> getJournal(String id) async => null;
+
+  @override
+  Future<JournalEntry> createJournal(JournalEntry entry) async => entry;
+
+  @override
+  Future<JournalEntry> updateJournal(JournalEntry entry) async => entry;
+
+  @override
+  Future<void> deleteJournal(String id) async {}
+
+  @override
+  Future<List<JournalElement>> getElements(String journalId) async => [];
+
+  @override
+  Future<JournalElement> addElement(JournalElement element) async => element;
+
+  @override
+  Future<JournalElement> updateElement(JournalElement element) async => element;
+
+  @override
+  Future<void> removeElement(String elementId) async {}
+}