feat: 三端抽屉重构 + 配色系统更新 + 后台管理页精调 + 键盘抬起组件

## 抽屉重构
- admin_drawer / doctor_drawer / health_drawer 三端抽屉全部重做
- drawer_shell 增强

## 配色系统
- app_colors / app_module_visuals / app_theme 更新
- app.dart 启动流程调整

## 后台管理页
- admin_doctors_page 大幅重构(+251)
- admin_home / doctor_dashboard / doctor_reports / doctor_home / doctor_followups / doctor_settings 精调

## 患者端
- home_page / chat_messages_view / medication_list / notification_center / remaining_pages / exercise_plan / device / diet / consultation 微调

## 新增
- keyboard_lift.dart: 键盘抬起处理组件
- AGENTS.md: agent 指引文档

## 其他
- api_client IP 适配
- app_future_view 增强
- data_providers 调整
- secondary_page_visuals_test 更新

health_app/lib/core/app_theme.dart

@@ -548,6 +548,7 @@ class GradientScaffold extends StatelessWidget {
   final Widget? drawer;
   final Widget? bottomNavigationBar;
   final bool extendBody;
+  final bool resizeToAvoidBottomInset;
 
   const GradientScaffold({
     super.key,
@@ -557,6 +558,7 @@ class GradientScaffold extends StatelessWidget {
     this.drawer,
     this.bottomNavigationBar,
     this.extendBody = false,
+    this.resizeToAvoidBottomInset = true,
   });
 
   @override
@@ -572,6 +574,7 @@ class GradientScaffold extends StatelessWidget {
     drawer: drawer,
     bottomNavigationBar: bottomNavigationBar,
     extendBody: extendBody,
+    resizeToAvoidBottomInset: resizeToAvoidBottomInset,
   );
 }