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/api/file.ts

@@ -0,0 +1,64 @@
+import request from "@/utils/request";
+
+const FileAPI = {
+  /** 上传文件 （传入 FormData，上传进度回调） */
+  upload(formData: FormData, onProgress?: (percent: number) => void) {
+    return request<any, FileInfo>({
+      url: "/api/v1/files",
+      method: "post",
+      data: formData,
+      headers: { "Content-Type": "multipart/form-data" },
+      onUploadProgress: (progressEvent) => {
+        if (progressEvent.total) {
+          const percent = Math.round((progressEvent.loaded * 100) / progressEvent.total);
+          onProgress?.(percent);
+        }
+      },
+    });
+  },
+
+  /** 上传文件（传入 File） */
+  uploadFile(file: File) {
+    const formData = new FormData();
+    formData.append("file", file);
+    return request<any, FileInfo>({
+      url: "/api/v1/files",
+      method: "post",
+      data: formData,
+      headers: { "Content-Type": "multipart/form-data" },
+    });
+  },
+
+  /** 删除文件 */
+  delete(filePath?: string) {
+    return request({
+      url: "/api/v1/files",
+      method: "delete",
+      params: { filePath },
+    });
+  },
+
+  /** 下载文件 */
+  download(url: string, fileName?: string) {
+    return request({
+      url,
+      method: "get",
+      responseType: "blob",
+    }).then((res) => {
+      const blob = new Blob([res.data]);
+      const a = document.createElement("a");
+      const urlObject = window.URL.createObjectURL(blob);
+      a.href = urlObject;
+      a.download = fileName || "下载文件";
+      a.click();
+      window.URL.revokeObjectURL(urlObject);
+    });
+  },
+};
+
+export default FileAPI;
+
+export interface FileInfo {
+  name: string;
+  url: string;
+}