fix download static api to return correct content-type

src/modules/static/static.controller.ts

@@ -23,6 +23,7 @@ export class StaticController extends Controller {
 		return res
 			.status(200)
 			.header("Cross-Origin-Resource-Policy", "cross-origin")
+			.header("Content-Type", file.mimeType)
 			.send(file.buffer);
 	}