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

backend/src/schemas/__init__.py

@@ -1,32 +1,47 @@
 """Centralized shared schemas for cross-module contracts."""
 
-from schemas.inbox.messages import InboxMessageStatus, InboxMessageType
-from schemas.schedule.items import (
-    AttachmentType,
+from schemas.inbox.messages import (
     CalendarContent,
     CalendarDeleteContent,
     CalendarInviteContent,
     CalendarUpdateContent,
+    FriendshipContent,
+    InboxMessageContent,
+    InboxMessageStatus,
+    InboxMessageType,
+    parse_calendar_content,
+)
+from schemas.invite_codes import InviteCodeRewardConfig
+from schemas.memories import MemoryContent
+from schemas.messages import AgentChatMessageMetadata
+from schemas.schedule.items import (
+    AttachmentType,
     ScheduleItemMetadata,
     ScheduleItemMetadataAttachment,
     ScheduleItemSourceType,
     ScheduleItemStatus,
-    parse_calendar_content,
 )
+from schemas.sessions import SessionStateSnapshot
 from schemas.user.context import UserContext
 
 __all__ = [
+    "AgentChatMessageMetadata",
     "AttachmentType",
     "CalendarContent",
     "CalendarDeleteContent",
     "CalendarInviteContent",
     "CalendarUpdateContent",
+    "FriendshipContent",
+    "InboxMessageContent",
     "InboxMessageStatus",
     "InboxMessageType",
+    "InviteCodeRewardConfig",
+    "MemoryContent",
     "ScheduleItemMetadata",
     "ScheduleItemMetadataAttachment",
     "ScheduleItemSourceType",
     "ScheduleItemStatus",
+    "SessionStateSnapshot",
     "UserContext",
     "parse_calendar_content",
 ]