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/system/user/index.vue

@@ -253,15 +253,15 @@ import { useDebounceFn } from "@vueuse/core";
 import { ElMessage, ElMessageBox, type FormInstance } from "element-plus";
 
 // ==================== 3. 类型定义 ====================
-import type { UserForm, UserPageQuery, UserPageVO } from "@/api/system/user-api";
+import type { UserForm, UserPageQuery, UserPageVO } from "@/api/system/user";
 
 // ==================== 3.5 工具函数 ====================
 import { downloadFile } from "@/utils";
 import { VALIDATORS } from "@/constants";
 // ==================== 4. API 服务 ====================
-import UserAPI from "@/api/system/user-api";
-import DeptAPI from "@/api/system/dept-api";
-import RoleAPI from "@/api/system/role-api";
+import UserAPI from "@/api/system/user";
+import DeptAPI from "@/api/system/dept";
+import RoleAPI from "@/api/system/role";
 
 // ==================== 5. Store ====================
 import { useUserStore, useAppStore } from "@/store";