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/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',