fix(deploy): take the Gitea address for Android updates from git remote

The server kept the git.example.lan placeholder from .env.example, so the
/android page and in-app updates had no release. install.sh and update.sh now
fill GITEA_URL and GITEA_REPO from the clone's origin (https, ssh and scp
forms, credentials stripped) when they are empty or still the placeholder,
and the API treats the placeholder as not configured.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/.env.example

@@ -45,6 +45,8 @@ SUPPORTED_LOCALES=ru,en
 MIN_ANDROID_VERSION_CODE=0
 
 # --- Самообновление Android (M5) ---
-GITEA_URL=https://git.example.lan
-GITEA_REPO=owner/pipu-music
+# Пусто — install.sh и update.sh возьмут из origin клона (например, https://gitea.example.com и owner/pipu-music).
+# Если сервер не видит Gitea по внешнему адресу, укажите внутренний: GITEA_URL=http://10.0.0.5:3000
+GITEA_URL=
+GITEA_REPO=
 GITEA_TOKEN=