style(frontend): 统一核心模块代码风格

- Composables: 优化 OAuth 相关 hooks 代码格式
- Stores: 规范状态管理模块格式
- Types: 统一类型定义格式
- Utils: 优化工具函数格式
- App.vue & style.css: 调整全局样式和主组件格式

frontend/src/stores/index.ts

@@ -3,9 +3,9 @@
  * Central export point for all application stores
  */
 
-export { useAuthStore } from './auth';
-export { useAppStore } from './app';
+export { useAuthStore } from './auth'
+export { useAppStore } from './app'
 
 // Re-export types for convenience
-export type { User, LoginRequest, RegisterRequest, AuthResponse } from '@/types';
-export type { Toast, ToastType, AppState } from '@/types';
+export type { User, LoginRequest, RegisterRequest, AuthResponse } from '@/types'
+export type { Toast, ToastType, AppState } from '@/types'