feat: UI全面改造 + 后端多项修复

【后端修复】
- 删除diet/consultation agent假工具声明
- 修复DayOfWeek实体注释
- 修复Vision API content序列化
- cleanup_service级联删除修复
- 用药提醒时区偏差修复
- 统一DateTime处理(UtcNow+8)
- 新增UTC DateTime JSON转换器

【前端UI重构】
- 配色体系全面更新(#8B5CF6淡紫+#F0ECFF背景)
- 登录页重设计
- 首页重设计(透明顶栏、渐变背景、胶囊输入区)
- 聊天卡片加白蓝边框、渐变标题
- 侧边栏重构(渐变背景、合并顶部、删除底部设置)
- 确认卡片可编辑字段恢复
- 所有子页面加返回按钮
- catch异常加日志
- 删除后refresh provider缓存

health_app/lib/pages/settings/settings_pages.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shadcn_ui/shadcn_ui.dart';
+import '../../core/app_colors.dart';
 import '../../core/app_theme.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/auth_provider.dart';
@@ -10,15 +11,12 @@ class SettingsPage extends ConsumerWidget {
   const SettingsPage({super.key});
 
   @override Widget build(BuildContext context, WidgetRef ref) {
-    final theme = ShadTheme.of(context);
-
     return Scaffold(
-      backgroundColor: theme.colorScheme.background,
+      backgroundColor: AppColors.background,
       appBar: AppBar(
-        backgroundColor: theme.colorScheme.card,
-        elevation: 0,
-        leading: IconButton(icon: Icon(LucideIcons.chevronLeft, color: theme.colorScheme.foreground), onPressed: () => popRoute(ref)),
-        title: Text('设置', style: TextStyle(fontSize: 21, fontWeight: FontWeight.w600, color: theme.colorScheme.foreground)),
+        backgroundColor: AppColors.cardBackground,
+        leading: IconButton(icon: const Icon(LucideIcons.chevronLeft, color: AppColors.textPrimary), onPressed: () => popRoute(ref)),
+        title: const Text('设置', style: TextStyle(fontSize: 21, fontWeight: FontWeight.w600, color: AppColors.textPrimary)),
         centerTitle: true,
       ),
       body: SafeArea(child: SingleChildScrollView(
@@ -26,10 +24,8 @@ class SettingsPage extends ConsumerWidget {
         child: Column(children: [
           const SizedBox(height: AppTheme.sMd),
           AppMenuItem(icon: LucideIcons.bell, title: '消息通知', onTap: () => pushRoute(ref, 'notificationPrefs')),
-          AppMenuItem(icon: LucideIcons.pill, title: '用药提醒', subtitle: 'mmHg / mmol/L', onTap: () => pushRoute(ref, 'medications')),
-          AppMenuItem(icon: LucideIcons.database, title: '数据导出', onTap: () {}),
-          AppMenuItem(icon: LucideIcons.type, title: '字体大小', trailing: 'v1.0.0', onTap: () {}),
-          AppMenuItem(icon: LucideIcons.sprayCan, title: '清除缓存', subtitle: '73.2 MB', onTap: () {}),
+          AppMenuItem(icon: LucideIcons.type, title: '字体大小', subtitle: '老年版', onTap: () {}),
+          AppMenuItem(icon: LucideIcons.sprayCan, title: '清除缓存', onTap: () {}),
           AppMenuItem(icon: LucideIcons.info, title: '关于健康管家', onTap: () => pushRoute(ref, 'staticText', params: {'type': 'about'})),
           AppMenuItem(icon: LucideIcons.shield, title: '隐私协议', onTap: () => pushRoute(ref, 'staticText', params: {'type': 'privacy'})),
           const SizedBox(height: 30),
@@ -40,10 +36,10 @@ class SettingsPage extends ConsumerWidget {
               height: 50,
               alignment: Alignment.center,
               decoration: BoxDecoration(
-                border: Border.all(color: theme.colorScheme.destructive.withAlpha(80)),
+                border: Border.all(color: AppColors.error.withAlpha(80)),
                 borderRadius: BorderRadius.circular(AppTheme.rPill),
               ),
-              child: Text('退出登录', style: TextStyle(fontSize: 19, color: theme.colorScheme.destructive, fontWeight: FontWeight.w500)),
+              child: const Text('退出登录', style: TextStyle(fontSize: 19, color: AppColors.error, fontWeight: FontWeight.w500)),
             ),
           ),
         ]),
@@ -52,16 +48,15 @@ class SettingsPage extends ConsumerWidget {
   }
 
   Future<void> _logout(BuildContext context, WidgetRef ref) async {
-    final theme = ShadTheme.of(context);
     final ok = await showDialog<bool>(
       context: context,
       builder: (ctx) => AlertDialog(
         shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(AppTheme.rXl)),
-        title: Text('退出登录', style: TextStyle(color: theme.colorScheme.foreground)),
-        content: Text('确定退出？', style: TextStyle(color: theme.colorScheme.mutedForeground)),
+        title: const Text('退出登录'),
+        content: const Text('确定退出？'),
         actions: [
-          TextButton(onPressed: () => Navigator.pop(ctx, false), child: Text('取消', style: TextStyle(color: theme.colorScheme.mutedForeground))),
-          TextButton(onPressed: () => Navigator.pop(ctx, true), child: Text('确定', style: TextStyle(color: theme.colorScheme.destructive))),
+          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('取消')),
+          TextButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('确定', style: TextStyle(color: AppColors.error))),
         ],
       ),
     );