multipart middleware (#5809)

* fix: multipart middleware

* fix: reviews

server/routes/api/BaseSchema.ts

@@ -1,8 +1,10 @@
+import formidable from "formidable";
 import { z } from "zod";
 
 const BaseSchema = z.object({
   body: z.unknown(),
   query: z.unknown(),
+  file: z.custom<formidable.File>().optional(),
 });
 
 export default BaseSchema;