fix: seed app.ini into writable config volume for Gitea 1.24+

Gitea 1.24+ persists settings back to app.ini on boot (e.g. WORK_PATH).
Mounting app.ini directly as a read-only swarm config makes that write
fail (logged error, possible repo-access bugs). Mount the rendered config
as app.ini.init and seed a writable copy in the config volume instead.

abra.sh

@@ -1,5 +1,5 @@
 export APP_INI_VERSION=v23
-export DOCKER_SETUP_SH_VERSION=v1
+export DOCKER_SETUP_SH_VERSION=v3
 export PG_BACKUP_VERSION=v1
 
 abra_backup_app() {