feat: 完善模型管理功能

- 新增模型 API 路由，支持 CRUD 和测试连接
- 支持 MiniMax、GLM、OpenAI Compatible 三种供应商
- 添加连接状态持久化 (untested/connected/disconnected)
- 修复 CORS 和数据库模型兼容性问题
- 前端 UI 优化：供应商默认 API 地址自动填充

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/api/index.ts

@@ -1,6 +1,6 @@
 import axios from 'axios'
 import type { AxiosInstance } from 'axios'
-import type { Project, ProjectCreate, ProjectUpdate } from '@/types'
+import type { Project, ProjectCreate, ProjectUpdate, Model, ModelCreate } from '@/types'
 
 const request: AxiosInstance = axios.create({
   baseURL: import.meta.env.PROD
@@ -91,4 +91,14 @@ export const evalApi = {
   getResults: (projectId: string, taskId: string) => request.get(`/projects/${projectId}/eval-tasks/${taskId}`)
 }
 
+export const modelApi = {
+  list: () => request.get<Model[]>('/models/'),
+  get: (id: string) => request.get<Model>(`/models/${id}`),
+  create: (data: ModelCreate) => request.post<{ id: string }>('/models/', data),
+  update: (id: string, data: Partial<Model>) => request.put<Model>(`/models/${id}`, data),
+  delete: (id: string) => request.delete(`/models/${id}`),
+  setDefault: (id: string) => request.post(`/models/${id}/set-default`),
+  test: (id: string) => request.post<{ success: boolean; message: string }>(`/models/${id}/test`)
+}
+
 export default request