feat: UI 系统中心化 + 趋势图重构 + 法律文档 H5 上线

- UI 系统: 新增 design_tokens / module_visuals / app_buttons / app_status_badge / app_toast / ai_content 六个共享模块; 28 个页面接入, SnackBar 全部替换为 AppToast
- 趋势图: 直线折线 + 渐变填充 + 阴影; 去网格线; X 轴日+月份分隔; Y 轴整数刻度最多 4 个; 点击数据点/录入记录显示上方浮层, 选中点变实心
- 法律文档 H5: 后端 wwwroot 托管隐私政策/服务协议/关于/个人信息收集清单/第三方 SDK 清单 + 索引页; Program.cs 启用 UseDefaultFiles + UseStaticFiles
- 其他: auth_provider 登录流程调整; api_client IP 适配; 主页智能体栏间距优化

health_app/lib/pages/doctor/doctor_followup_edit_page.dart

@@ -4,6 +4,7 @@ import '../../core/app_colors.dart';
 import '../../core/app_theme.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/auth_provider.dart';
+import '../../widgets/app_toast.dart';
 
 final _ptsSimple = FutureProvider<List<Map<String, dynamic>>>((ref) async {
   final api = ref.read(apiClientProvider);
@@ -275,11 +276,10 @@ class _DoctorFollowUpEditPageState
   }
 
   void _snack(String msg, {bool ok = false}) {
-    ScaffoldMessenger.of(context).showSnackBar(
-      SnackBar(
-        content: Text(msg),
-        backgroundColor: ok ? AppColors.success : AppColors.error,
-      ),
+    AppToast.show(
+      context,
+      msg,
+      type: ok ? AppToastType.success : AppToastType.error,
     );
   }
 }

health_app/lib/pages/doctor/doctor_profile_page.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../../core/app_colors.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/auth_provider.dart';
+import '../../widgets/app_toast.dart';
 
 final _docProfileProvider = FutureProvider<Map<String, dynamic>?>((ref) async {
   final api = ref.read(apiClientProvider);
@@ -112,21 +113,11 @@ class _DoctorProfileEditPageState extends ConsumerState<DoctorProfileEditPage> {
           );
       ref.invalidate(_docProfileProvider);
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('保存成功'),
-            backgroundColor: AppColors.success,
-          ),
-        );
+        AppToast.show(context, '保存成功', type: AppToastType.success);
       }
     } catch (_) {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('保存失败'),
-            backgroundColor: AppColors.error,
-          ),
-        );
+        AppToast.show(context, '保存失败', type: AppToastType.error);
       }
     } finally {
       if (mounted) setState(() => _saving = false);

health_app/lib/pages/doctor/doctor_report_detail_page.dart

@@ -4,6 +4,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../../core/app_colors.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/auth_provider.dart';
+import '../../widgets/app_toast.dart';
 
 final _reportDetailProvider =
     FutureProvider.family<Map<String, dynamic>?, String>((ref, id) async {
@@ -54,9 +55,7 @@ class _DoctorReportDetailPageState
 
   Future<void> _submitReview() async {
     if (_severity.isEmpty) {
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(const SnackBar(content: Text('请选择严重程度')));
+      AppToast.show(context, '请选择严重程度', type: AppToastType.warning);
       return;
     }
     setState(() => _submitting = true);
@@ -73,18 +72,11 @@ class _DoctorReportDetailPageState
       setState(() => _submitted = true);
       ref.invalidate(_reportDetailProvider(widget.id));
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
-            content: Text('审核提交成功'),
-            backgroundColor: AppColors.success,
-          ),
-        );
+        AppToast.show(context, '审核提交成功', type: AppToastType.success);
       }
     } catch (e) {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text('提交失败: $e'), backgroundColor: AppColors.error),
-        );
+        AppToast.show(context, '提交失败: $e', type: AppToastType.error);
       }
     } finally {
       if (mounted) setState(() => _submitting = false);