Replace '<3' with '❤️' in translations

Replace ASCII heart "<3" with Unicode heart emoji "❤️" in logout strings across translation files to improve visual consistency and rendering. Updated files in internal/web/translation for: ar-EG, en-US, es-ES, fa-IR, id-ID, ja-JP, pt-BR, ru-RU, tr-TR, uk-UA, vi-VN, zh-CN, and zh-TW.

internal/web/translation/vi-VN.json

@@ -6,7 +6,7 @@
   "cancel": "Hủy bỏ",
   "close": "Đóng",
   "save": "Lưu",
-  "logout": "Đăng xuất <3",
+  "logout": "Đăng xuất ❤️",
   "create": "Tạo",
   "add": "Thêm",
   "remove": "Xóa",