refactor: 移除 LiteLLM proxy 架构，后端直连 Provider API

- 移除 backend/scripts/build_litellm_proxy_config.py
- 简化 LiteLLMService，移除 run_completion_with_cost 方法
- AgentScopeRunner 改为从 LlmFactory 获取 api_base 和 api_key
- 部署配置移除 litellm/litellm-config-job 服务
- Flutter 新增 AuthBootScreen 引导页
- Android 添加通知权限 (POST_NOTIFICATIONS, RECEIVE_BOOT_COMPLETED, SCHEDULE_EXACT_ALARM)
- 优化 LocalNotificationService 调度失败 fallback
- 更新 manifest.json (version 3)

apps/lib/core/notifications/local_notification_service.dart

@@ -76,16 +76,29 @@ class LocalNotificationService {
       ),
     );
 
-    await _plugin.zonedSchedule(
-      notificationId,
-      event.title,
-      _buildReminderBody(event, reminderMinutes),
-      scheduledAt,
-      details,
-      androidScheduleMode: AndroidScheduleMode.exactAllowWhileIdle,
-      uiLocalNotificationDateInterpretation:
-          UILocalNotificationDateInterpretation.absoluteTime,
-    );
+    try {
+      await _plugin.zonedSchedule(
+        notificationId,
+        event.title,
+        _buildReminderBody(event, reminderMinutes),
+        scheduledAt,
+        details,
+        androidScheduleMode: AndroidScheduleMode.exactAllowWhileIdle,
+        uiLocalNotificationDateInterpretation:
+            UILocalNotificationDateInterpretation.absoluteTime,
+      );
+    } catch (_) {
+      await _plugin.zonedSchedule(
+        notificationId,
+        event.title,
+        _buildReminderBody(event, reminderMinutes),
+        scheduledAt,
+        details,
+        androidScheduleMode: AndroidScheduleMode.inexactAllowWhileIdle,
+        uiLocalNotificationDateInterpretation:
+            UILocalNotificationDateInterpretation.absoluteTime,
+      );
+    }
   }
 
   Future<void> cancelEventReminder(String eventId) async {

apps/lib/core/router/app_router.dart

@@ -3,6 +3,7 @@ import '../../features/auth/presentation/bloc/auth_bloc.dart';
 import '../../features/auth/presentation/bloc/auth_state.dart';
 import 'go_router_refresh_stream.dart';
 import '../../features/auth/ui/screens/login_screen.dart';
+import '../../features/auth/ui/screens/auth_boot_screen.dart';
 import '../../features/auth/ui/screens/register_screen.dart';
 import '../../features/auth/ui/screens/register_verification_screen.dart';
 import '../../features/auth/ui/screens/reset_password_screen.dart';
@@ -43,11 +44,14 @@ final _protectedRoutes = [
 
 GoRouter createAppRouter(AuthBloc authBloc) {
   return GoRouter(
-    initialLocation: '/',
+    initialLocation: '/boot',
     refreshListenable: GoRouterRefreshStream(authBloc.stream),
     redirect: (context, state) {
       final authState = authBloc.state;
       final isAuthenticated = authState is AuthAuthenticated;
+      final isAuthChecking =
+          authState is AuthInitial || authState is AuthLoading;
+      final isBootRoute = state.matchedLocation == '/boot';
       final isAuthRoute =
           state.matchedLocation == '/' ||
           state.matchedLocation.startsWith('/login') ||
@@ -56,6 +60,12 @@ GoRouter createAppRouter(AuthBloc authBloc) {
         (route) => state.matchedLocation.startsWith(route),
       );
 
+      if (isAuthChecking && !isBootRoute) {
+        return '/boot';
+      }
+      if (!isAuthChecking && isBootRoute) {
+        return isAuthenticated ? '/home' : '/';
+      }
       if (!isAuthenticated && isProtected) {
         return '/';
       }
@@ -65,6 +75,10 @@ GoRouter createAppRouter(AuthBloc authBloc) {
       return null;
     },
     routes: [
+      GoRoute(
+        path: '/boot',
+        builder: (context, state) => const AuthBootScreen(),
+      ),
       GoRoute(path: '/', builder: (context, state) => const LoginScreen()),
       GoRoute(
         path: '/calendar/events/:id',

apps/lib/features/auth/ui/screens/auth_boot_screen.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+
+import '../../../../core/theme/design_tokens.dart';
+import '../../../../shared/widgets/app_loading_indicator.dart';
+
+class AuthBootScreen extends StatelessWidget {
+  const AuthBootScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const Scaffold(
+      backgroundColor: AppColors.authBackgroundTop,
+      body: SafeArea(
+        child: Center(
+          child: AppLoadingIndicator(
+            variant: AppLoadingVariant.surface,
+            size: 28,
+            strokeWidth: 2.5,
+            color: AppColors.authPrimaryButton,
+            trackColor: AppColors.authPrimaryButtonDisabled,
+          ),
+        ),
+      ),
+    );
+  }
+}

apps/lib/features/calendar/ui/widgets/create_event_sheet.dart

@@ -638,7 +638,11 @@ class _CreateEventSheetState extends State<CreateEventSheet>
       try {
         final notificationService = sl<LocalNotificationService>();
         await notificationService.upsertEventReminder(saved);
-      } catch (_) {}
+      } catch (_) {
+        if (mounted) {
+          Toast.show(context, '提醒创建失败，请检查通知权限', type: ToastType.warning);
+        }
+      }
 
       widget.onSaved?.call();
       if (mounted) {