refactor: 重命名 API 文件并更新引用路径

- 重命名 13 个 API 文件，去掉 -api 后缀
  * src/api/auth-api.ts  auth.ts
  * src/api/codegen-api.ts  codegen.ts
  * src/api/file-api.ts  file.ts
  * src/api/system/*.ts (9个文件)

- 批量更新 50+ 处 API 引用路径
- 修复 websocket 和枚举导入路径
- 确保零编码问题（使用 UTF-8 编码）

src/views/demo/curd-single.vue

@@ -68,10 +68,10 @@
 </template>
 
 <script setup lang="ts">
-import UserAPI from "@/api/system/user-api";
-import DeptAPI from "@/api/system/dept-api";
-import RoleAPI from "@/api/system/role-api";
-import type { UserForm, UserPageQuery } from "@/api/system/user-api";
+import UserAPI from "@/api/system/user";
+import DeptAPI from "@/api/system/dept";
+import RoleAPI from "@/api/system/role";
+import type { UserForm, UserPageQuery } from "@/api/system/user";
 import type { IObject, IModalConfig, IContentConfig, ISearchConfig } from "@/components/CURD/types";
 import { DeviceEnum } from "@/enums/settings/device-enum";
 import { useAppStore } from "@/store";