fix:STT V2 기본 리전을 서울(asia-northeast3)로 변경

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

config/services.php

@@ -47,7 +47,7 @@
     'google' => [
         'credentials_path' => env('GOOGLE_APPLICATION_CREDENTIALS'),
         'storage_bucket' => env('GOOGLE_STORAGE_BUCKET'),
-        'location' => env('GOOGLE_STT_LOCATION', 'us-central1'),
+        'location' => env('GOOGLE_STT_LOCATION', 'asia-northeast3'),
     ],
 
     /*