refactor: move imports to top of file

Author: fulleni

routes/_middleware.dart

@@ -1,5 +1,5 @@
-import 'dart:convert';
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:dart_frog/dart_frog.dart';
@@ -430,7 +430,6 @@ Handler middleware(Handler handler) {
         ),
       )
 
-
       // --- 4. Authentication Service Providers (Auth Logic Dependencies) ---
       // PURPOSE: Provide the core services needed for authentication logic.
       // ORDER:   These MUST be provided BEFORE `authenticationProvider` and