feat: Update vehicle recommendation notification with review CC info

Change notification to English and add 1 CC review reward mention.

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

backend/app/api/notification.py

@@ -51,8 +51,8 @@ def notify_vehicle_recommended(db: Session, user_id: int, request_id: int, vehic
         db=db,
         user_id=user_id,
         notification_type="vehicle_recommended",
-        title="차량 추천 완료",
-        message=f"{vehicle_count}대의 차량이 추천되었습니다. 지금 확인해보세요!",
+        title="Vehicle Recommendation Ready",
+        message=f"{vehicle_count} vehicles have been recommended for you! Check them out now. Write a review after purchase and earn 1 CC reward.",
         link=f"/my-request",
         related_id=request_id,
         related_type="vehicle_request"