update nextcloud for file support

backend/src/types/multer.d.ts

@@ -0,0 +1,51 @@
+// Minimal type declaration for multer — replaced by @types/multer after npm install
+declare module 'multer' {
+  import { RequestHandler } from 'express';
+
+  interface StorageEngine {}
+
+  interface Options {
+    storage?: StorageEngine;
+    limits?: {
+      fileSize?: number;
+      files?: number;
+      fields?: number;
+    };
+  }
+
+  interface Multer {
+    single(fieldname: string): RequestHandler;
+    array(fieldname: string, maxCount?: number): RequestHandler;
+    none(): RequestHandler;
+  }
+
+  interface MulterStatic {
+    (options?: Options): Multer;
+    memoryStorage(): StorageEngine;
+    diskStorage(options: any): StorageEngine;
+  }
+
+  const multer: MulterStatic;
+  export default multer;
+}
+
+declare namespace Express {
+  interface Request {
+    file?: {
+      fieldname: string;
+      originalname: string;
+      encoding: string;
+      mimetype: string;
+      size: number;
+      buffer: Buffer;
+    };
+    files?: {
+      fieldname: string;
+      originalname: string;
+      encoding: string;
+      mimetype: string;
+      size: number;
+      buffer: Buffer;
+    }[];
+  }
+}