feat(settings): 收藏列表 + 最近呼叫全量实现（#42~#45）

## 收藏（Gitea #42~#45）
- `FetchFavoritesRequest` / `DeleteFavoriteRequest`：ApiRequestable，对齐 iOS FavouriteService
- `FetchFavoritesUseCase`：GET 分页拉取 → upsert FavoriteRepository
- `DeleteFavoriteUseCase`：POST delete → 同步删本地 DB
- `FavoritesViewModel`：分页/刷新/加载更多/删除，DB Stream 驱动
- `FavoritesPage`：列表 + RefreshIndicator + Dismissible 左滑删除 + 类型图标 + 空状态
- `AppRouteName.settingsFavorites` + 路由注册 + auth guard
- `settings_page.dart` 收藏行 onTap 接入导航

## 最近呼叫（框架，API 对接待续）
- `CallLogRequest` / `FetchCallLogsUseCase` / `RecentCallsViewModel`
- `RecentCallsPage`：双 Tab（全部/未接）+ _CallLogTile（图标/时长/时间）
- `AppRouteName.settingsRecentCalls` + 路由注册

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/im_app/lib/app/router/guards/auth_guard.dart

@@ -45,6 +45,8 @@ String? authGuard(AuthNotifier authNotifier, GoRouterState state) {
     case AppRouteName.settingsLanguage:
     case AppRouteName.settingsNetworkDiagnostics:
     case AppRouteName.settingsAbout:
+    case AppRouteName.settingsFavorites:
+    case AppRouteName.settingsRecentCalls:
     case AppRouteName.chatDBTest:
       // 受保护路由 → 未登录跳登录页
       return isLoggedIn ? null : AppRouteName.login.path;