feat: improve error handling and code quality

后端改进:
- 添加统一异常处理系统 (exceptions.py, response.py)
- 实现自定义异常类 (ValidationError, AuthorizationError, ResourceNotFoundError, BusinessLogicError)
- 配置全局异常处理器,统一 API 错误响应格式
- 迁移业务逻辑错误到自定义异常 (users.py, auth.py)
- 添加 SQL LIKE 通配符转义,防止通配符滥用
- 使用 EmailStr 进行邮箱格式验证
- 移除敏感字段暴露 (jwt_sub)

前端改进:
- 配置 ESLint 9 (flat config) 和 Prettier
- 修复所有 ESLint 错误和警告
- 移除未使用的变量和导入
- 为组件添加 PropTypes 默认值
- 统一代码格式和风格

frontend/package.json

@@ -6,7 +6,9 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "lint": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs --fix",
+    "format": "prettier --write ."
   },
   "dependencies": {
     "@ant-design/icons-vue": "^7.0.1",
@@ -17,9 +19,14 @@
     "vue-router": "^4.6.4"
   },
   "devDependencies": {
+    "@eslint/js": "^9.39.2",
     "@vitejs/plugin-vue": "^6.0.1",
+    "@vue/eslint-config-prettier": "^10.2.0",
     "autoprefixer": "^10.4.23",
+    "eslint": "^9.39.2",
+    "eslint-plugin-vue": "^10.6.2",
     "postcss": "^8.5.6",
+    "prettier": "^3.7.4",
     "tailwindcss": "^3.4.19",
     "vite": "^7.2.4"
   }