refactor: 简化模型管理，移除启用/禁用，优化测试和布局

- 移除供应商/模型启用禁用能力，清理DB schema/migration/API/前端
- 供应商测试改为Base URL连通性+/models探测
- 新增POST /api/models/test模型连接测试
- 新增GET /api/providers/options专用供应商选项接口
- 统一工具栏为ModelsToolbar，参考项目管理布局
- 模型弹窗优化：默认能力、响应式3列标签、并排数值
- 前后端正整数校验、供应商下拉loading/error/empty状态
- 表格列宽统一，操作列/名称列固定宽度

src/server/server.ts

@@ -67,16 +67,10 @@ export function startServer(options: StartServerOptions) {
           return handleUpdateModel(req, db, mode);
         },
       },
-      "/api/models/:id/disable": {
+      "/api/models/test": {
         POST: async (req) => {
-          const { handleDisableModel } = await import("./routes/models/disable");
-          return handleDisableModel(req, db, mode);
-        },
-      },
-      "/api/models/:id/enable": {
-        POST: async (req) => {
-          const { handleEnableModel } = await import("./routes/models/enable");
-          return handleEnableModel(req, db, mode);
+          const { handleTestModelConfig } = await import("./routes/models/test");
+          return handleTestModelConfig(req, db, mode);
         },
       },
       "/api/projects": {
@@ -139,22 +133,10 @@ export function startServer(options: StartServerOptions) {
           return handleUpdateProvider(req, db, mode);
         },
       },
-      "/api/providers/:id/disable": {
-        POST: async (req) => {
-          const { handleDisableProvider } = await import("./routes/providers/disable");
-          return handleDisableProvider(req, db, mode);
-        },
-      },
-      "/api/providers/:id/enable": {
-        POST: async (req) => {
-          const { handleEnableProvider } = await import("./routes/providers/enable");
-          return handleEnableProvider(req, db, mode);
-        },
-      },
-      "/api/providers/:id/test": {
-        POST: async (req) => {
-          const { handleTestProvider } = await import("./routes/providers/test");
-          return handleTestProvider(req, db, mode);
+      "/api/providers/options": {
+        GET: async () => {
+          const { handleListProviderOptions } = await import("./routes/providers/options");
+          return handleListProviderOptions(db, mode);
         },
       },
       "/api/providers/test": {