fix(app): 全链路验证修复 — 编译错误/CORS/迁移/启动脚本

前端修复:
- calendar_page: 移除不存在的 JournalEntry.content getter
- responsive_scaffold: 移除不存在的 notchThickness 参数
- splash_page: SingleTickerProvider → TickerProvider (多 AnimationController)
- profile_page: UserRoleType.name → .code (修复运行时崩溃)
- 导入缺失的 user.dart

后端修复:
- class_service: generate_class_code 取 UUID 后6位(随机部分)避免碰撞
- diary_role_seed: 移除不存在的 id 列,使用复合主键 ON CONFLICT

基础设施:
- config/default.toml: CORS 改为通配符(开发模式)
- scripts/dev.sh: 统一启动脚本(自动清理端口)
- docs/opendesign/: Open Design 设计规格 HTML 原型稿

验证结果: flutter analyze 0 error, cargo test 77/77 通过, 17个页面全部渲染正常

app/lib/features/settings/views/settings_page.dart

@@ -3,6 +3,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:nuanji_app/core/theme/app_colors.dart';
+import 'package:nuanji_app/core/theme/app_radius.dart';
 import 'package:nuanji_app/features/profile/bloc/settings_bloc.dart';
 
 /// 设置页面
@@ -92,7 +93,7 @@ class _ThemeSelectorCard extends StatelessWidget {
     return Card(
       elevation: 0,
       shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(22),
+        borderRadius: AppRadius.lgBorder,
         side: BorderSide(color: colorScheme.outlineVariant),
       ),
       child: Padding(
@@ -165,7 +166,7 @@ class _AboutCard extends StatelessWidget {
     return Card(
       elevation: 0,
       shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(22),
+        borderRadius: AppRadius.lgBorder,
         side: BorderSide(color: colorScheme.outlineVariant),
       ),
       child: Column(
@@ -180,7 +181,7 @@ class _AboutCard extends StatelessWidget {
                   height: 56,
                   decoration: BoxDecoration(
                     color: AppColors.accent.withValues(alpha: 0.15),
-                    borderRadius: BorderRadius.circular(16),
+                    borderRadius: AppRadius.mdBorder,
                   ),
                   alignment: Alignment.center,
                   child: const Text('📝', style: TextStyle(fontSize: 28)),
@@ -294,7 +295,7 @@ class _LegalCard extends StatelessWidget {
     return Card(
       elevation: 0,
       shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(22),
+        borderRadius: AppRadius.lgBorder,
         side: BorderSide(color: colorScheme.outlineVariant),
       ),
       child: Column(