feat: add a platform-aware apps download page

Serve desktop and Android builds from the latest Gitea release on /download, and fix the desktop compile and CI flakes that blocked v1.3.0.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/i18n/locales/ru/common.json

@@ -41,7 +41,7 @@
     "menu": "Меню профиля",
     "settings": "Настройки",
     "logout": "Выйти",
-    "android_app": "Приложение для Android"
+    "download_apps": "Скачать приложения"
   },
   "roles": {
     "admin": "Администратор",