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/report/report_pages.dart

@@ -7,6 +7,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:image_picker/image_picker.dart';
 import '../../core/app_colors.dart';
+import '../../core/app_module_visuals.dart';
 import '../../core/app_theme.dart';
 import '../../core/api_client.dart' show baseUrl;
 import '../../core/navigation_provider.dart';
@@ -17,6 +18,13 @@ final reportProvider = NotifierProvider<ReportNotifier, ReportState>(
   ReportNotifier.new,
 );
 
+Duration? reportAnalysisPollDelay(int attempt) {
+  if (attempt > 15) return null;
+  if (attempt <= 2) return const Duration(seconds: 4);
+  if (attempt <= 5) return const Duration(seconds: 8);
+  return const Duration(seconds: 12);
+}
+
 class ReportState {
   final List<ReportItem> reports;
   final String? uploadingImage;
@@ -132,6 +140,7 @@ class Indicator {
 
 class ReportNotifier extends Notifier<ReportState> {
   Timer? _pollTimer;
+  int _pollAttempt = 0;
 
   @override
   ReportState build() {
@@ -185,12 +194,16 @@ class ReportNotifier extends Notifier<ReportState> {
     if (!hasAnalyzing) {
       _pollTimer?.cancel();
       _pollTimer = null;
+      _pollAttempt = 0;
       return;
     }
-    _pollTimer ??= Timer.periodic(
-      const Duration(seconds: 4),
-      (_) => loadReports(),
-    );
+    if (_pollTimer != null) return;
+    final delay = reportAnalysisPollDelay(++_pollAttempt);
+    if (delay == null) return;
+    _pollTimer = Timer(delay, () {
+      _pollTimer = null;
+      loadReports();
+    });
   }
 
   void fetchReportDetail(String reportId) async {
@@ -354,8 +367,9 @@ class ReportNotifier extends Notifier<ReportState> {
 class ReportListPage extends ConsumerWidget {
   const ReportListPage({super.key});
 
-  static const _reportBlue = Color(0xFF8B5CF6);
-  static const _reportCyan = Color(0xFF38BDF8);
+  static const _reportVisual = AppModuleVisuals.report;
+  static const _reportBlue = AppColors.report;
+  static const _reportCyan = Color(0xFF60A5FA);
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
@@ -407,7 +421,7 @@ class ReportListPage extends ConsumerWidget {
             EnterpriseHeader(
               title: '报告处理概览',
               subtitle: '上传检查报告后自动进行 AI 结构化解读',
-              icon: Icons.description_outlined,
+              icon: _reportVisual.icon,
               color: _reportBlue,
               accent: _reportCyan,
               showIcon: false,
@@ -564,11 +578,7 @@ class ReportListPage extends ConsumerWidget {
               color: _reportBlue.withValues(alpha: 0.08),
               borderRadius: BorderRadius.circular(50),
             ),
-            child: const Icon(
-              Icons.description_outlined,
-              size: 44,
-              color: _reportBlue,
-            ),
+            child: Icon(_reportVisual.icon, size: 44, color: _reportBlue),
           ),
           const SizedBox(height: 20),
           const Text(
@@ -625,11 +635,7 @@ class ReportListPage extends ConsumerWidget {
                       color: _reportBlue.withValues(alpha: 0.10),
                     ),
                   ),
-                  child: const Icon(
-                    Icons.description_outlined,
-                    size: 26,
-                    color: _reportBlue,
-                  ),
+                  child: Icon(_reportVisual.icon, size: 26, color: _reportBlue),
                 ),
                 const SizedBox(width: 14),
                 Expanded(