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/core/theme/app_theme.dart

@@ -1,4 +1,5 @@
 // 暖记主题入口 — 浅色/深色 ThemeData
+// 对齐 Open Design 原型稿设计系统
 
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart';
@@ -44,7 +45,7 @@ class AppTheme {
         shape: RoundedRectangleBorder(
           borderRadius: AppRadius.mdBorder,
           side: BorderSide(
-            color: colorScheme.outlineVariant.withValues(alpha: 0.3),
+            color: colorScheme.outlineVariant,
           ),
         ),
         color: colorScheme.surface,
@@ -102,7 +103,7 @@ class AppTheme {
       bottomNavigationBarTheme: BottomNavigationBarThemeData(
         type: BottomNavigationBarType.fixed,
         selectedItemColor: colorScheme.primary,
-        unselectedItemColor: colorScheme.onSurface.withValues(alpha: 0.5),
+        unselectedItemColor: colorScheme.onSurfaceVariant,
         backgroundColor: colorScheme.surface,
         elevation: 8,
       ),
@@ -115,15 +116,15 @@ class AppTheme {
         side: BorderSide.none,
       ),
 
-      // FloatingActionButton
+      // FloatingActionButton — 珊瑚色圆形凸起
       floatingActionButtonTheme: FloatingActionButtonThemeData(
-        shape: RoundedRectangleBorder(
-          borderRadius: AppRadius.mdBorder,
-        ),
+        backgroundColor: isLight ? AppColors.accent : AppColors.accentDark,
+        foregroundColor: isLight ? const Color(0xFFFFF8F0) : const Color(0xFF1A1614),
+        shape: const CircleBorder(),
         elevation: 4,
       ),
 
-      // Page transitions — 弹性曲线
+      // Page transitions — 弹性曲线 cubic-bezier(0.34, 1.56, 0.64, 1)
       pageTransitionsTheme: PageTransitionsTheme(
         builders: {
           TargetPlatform.android: _WarmCurveBuilder(),