feat: 优化前端 UI 组件与交互体验

- 优化日历、待办、消息等页面交互
- 更新 ChatBloc 与 UI Schema 渲染
- 优化联系人、首页、设置页面体验

apps/AGENTS.md

@@ -62,6 +62,16 @@ Follow lightweight testing strategy - prioritize value over coverage:
 - **MUST NOT** create custom SnackBar/Dialog/Banner feedback components.
 - **MUST NOT** use raw `ScaffoldMessenger` for feedback messaging.
 
+## 6.1) Loading Indicator System (MUST)
+
+- All loading spinners **MUST** use `AppLoadingIndicator` from `apps/lib/shared/widgets/app_loading_indicator.dart`.
+- **MUST NOT** use raw `CircularProgressIndicator` directly in feature/page code.
+- Use variants consistently:
+  - page/surface loading: `AppLoadingVariant.surface`
+  - inline small loading (list/search/section): `AppLoadingVariant.inline`
+  - button loading: `AppLoadingVariant.button`
+- If visual semantics are missing, extend `AppLoadingIndicator` variant mapping first; do not create ad-hoc loading styles in feature files.
+
 ## 7) Agent Chat (AG-UI Protocol) (MUST)
 
 Agent chat functionality **MUST** follow the AG-UI protocol. **Use the `ag-ui` skill** for protocol reference and implementation guidance.