feat: 添加视觉设计语言系统并重构认证页面UI

- 新增 visual_design_language.md 设计规范文档
- 新增 auth 设计 tokens (authBackground, authCard, authInput, feedback 系列等)
- 重构登录/注册/验证码/重置密码页面为新设计系统
- 新增 AuthHeroHeader, AuthSurfaceCard, AuthSection, AuthField, PasswordField 组件
- 重构 AppBanner 和 Toast 支持多类型配置 (info/success/warning/error)
- 后端 AgentScope: 重整 schemas/prompts/tools 作用域, 新增协议文档
- 更新 AGENTS.md 集成视觉设计语言约束

apps/lib/core/startup/auth_session_bootstrapper.dart

@@ -0,0 +1,38 @@
+import '../../features/auth/presentation/bloc/auth_state.dart';
+import '../../features/calendar/data/services/calendar_service.dart';
+import '../notifications/local_notification_service.dart';
+
+class AuthSessionBootstrapper {
+  AuthSessionBootstrapper({
+    required CalendarService calendarService,
+    required LocalNotificationService notificationService,
+  }) : _calendarService = calendarService,
+       _notificationService = notificationService;
+
+  final CalendarService _calendarService;
+  final LocalNotificationService _notificationService;
+
+  String? _syncedUserId;
+
+  Future<void> syncForAuthState(AuthState state) async {
+    if (state is! AuthAuthenticated) {
+      _syncedUserId = null;
+      return;
+    }
+
+    if (_syncedUserId == state.user.id) {
+      return;
+    }
+
+    _syncedUserId = state.user.id;
+
+    try {
+      final now = DateTime.now();
+      final end = now.add(const Duration(days: 90));
+      final events = await _calendarService.getEventsForRange(now, end);
+      await _notificationService.rebuildUpcomingReminders(events);
+    } catch (_) {
+      // ignore reminder bootstrap failures
+    }
+  }
+}

apps/lib/core/theme/design_tokens.dart

@@ -27,6 +27,8 @@ class AppColors {
   static const blue600 = Color(0xFF2563EB);
   static const blue500 = Color(0xFF3B82F6);
   static const blue400 = Color(0xFF60A5FA);
+  static const blue300 = Color(0xFF93C5FD);
+  static const blue200 = Color(0xFFBFDBFE);
   static const blue100 = Color(0xFFDBEAFE);
   static const blue50 = Color(0xFFEFF6FF);
 
@@ -81,6 +83,48 @@ class AppColors {
   static const appIconBorder = Color(0xFFC7DDFB);
   static const appTitle = Color(0xFF1E293B);
 
+  static const authBackgroundTop = Color(0xFFF4F8FF);
+  static const authBackgroundBottom = Color(0xFFF8FAFC);
+  static const authBackgroundOrb = Color(0xFFDCEBFF);
+  static const authCardBackground = Color(0xFFFCFDFE);
+  static const authCardBorder = Color(0xFFE5ECF6);
+  static const authCardHighlight = Color(0xFFFFFFFF);
+  static const authSectionBackground = Color(0xFFF7FAFE);
+  static const authSectionBorder = Color(0xFFE4EBF5);
+  static const authInputBackground = Color(0xFFF6F9FD);
+  static const authInputBorder = Color(0xFFD9E4F1);
+  static const authInputFocus = Color(0xFF8EB8F3);
+  static const authInputIcon = Color(0xFF8A9BB2);
+  static const authPrimaryButton = Color(0xFF2F6FD6);
+  static const authPrimaryButtonPressed = Color(0xFF245FC0);
+  static const authPrimaryButtonDisabled = Color(0xFFD9E3F2);
+  static const authPrimaryButtonText = Color(0xFFF8FBFF);
+  static const authSecondaryButtonBackground = Color(0xFFF4F8FF);
+  static const authSecondaryButtonBorder = Color(0xFFD8E4F6);
+  static const authSecondaryButtonText = Color(0xFF315D9C);
+  static const authLinkText = Color(0xFF356CC8);
+  static const authLinkMuted = Color(0xFF70839E);
+
+  static const feedbackInfoSurface = Color(0xFFF3F8FF);
+  static const feedbackInfoBorder = Color(0xFFD6E5FB);
+  static const feedbackInfoIcon = Color(0xFF2D6CDF);
+  static const feedbackInfoText = Color(0xFF26476F);
+
+  static const feedbackSuccessSurface = Color(0xFFF1FBF6);
+  static const feedbackSuccessBorder = Color(0xFFCDECD9);
+  static const feedbackSuccessIcon = Color(0xFF129268);
+  static const feedbackSuccessText = Color(0xFF1E5A46);
+
+  static const feedbackWarningSurface = Color(0xFFFFF8ED);
+  static const feedbackWarningBorder = Color(0xFFF4DFC0);
+  static const feedbackWarningIcon = Color(0xFFD68A18);
+  static const feedbackWarningText = Color(0xFF7A5821);
+
+  static const feedbackErrorSurface = Color(0xFFFFF4F3);
+  static const feedbackErrorBorder = Color(0xFFF1D2D0);
+  static const feedbackErrorIcon = Color(0xFFD14F4B);
+  static const feedbackErrorText = Color(0xFF7E3735);
+
   static const todoBg = Color(0xFFF8FAFC);
   static const todoCardBg = Color(0xFFFFFFFF);