refactor: 提取正则工具模块并清理废弃代码

前端:
- 新增 model-mapping-regex.ts 工具模块，统一正则验证和 LRU 缓存
- ModelMappingsTab/RoutingTab 重构为使用 computed 缓存匹配结果
- 移除多个组件中未使用的变量和函数
- 添加 HTMLImageElement/HTMLIFrameElement 到 ESLint 全局类型
- 修复 vitest 需要 --experimental-require-module 的问题

后端:
- 移除废弃的异步数据库支持 (get_async_db, AsyncSession)
- 将 async_utils 从 database/ 迁移到 utils/
- 改进 database.py 类型标注
- 修复 email 模块的 aiosmtplib 可选导入类型问题

frontend/src/views/user/ModelCatalog.vue

@@ -370,7 +370,7 @@ import UserModelDetailDrawer from './components/UserModelDetailDrawer.vue'
 import { useRowClick } from '@/composables/useRowClick'
 import { log } from '@/utils/logger'
 
-const { success, error: showError } = useToast()
+const { error: showError } = useToast()
 const { copyToClipboard } = useClipboard()
 
 // 状态

frontend/src/views/user/components/UserModelDetailDrawer.vue

@@ -351,7 +351,6 @@ import {
   Image as ImageIcon
 } from 'lucide-vue-next'
 import { useEscapeKey } from '@/composables/useEscapeKey'
-import { useToast } from '@/composables/useToast'
 import { useClipboard } from '@/composables/useClipboard'
 import Card from '@/components/ui/card.vue'
 import Badge from '@/components/ui/badge.vue'
@@ -375,7 +374,6 @@ const emit = defineEmits<{
   'toggleCapability': [modelName: string, capName: string]
 }>()
 
-const { success: showSuccess, error: showError } = useToast()
 const { copyToClipboard } = useClipboard()
 
 interface Props {