Align CI/CD with soroush method (DrSousan single-app pattern)

Audited against working Meezi/DrSousan pipelines. Fixes:
- Single docker-compose.yml is the production stack (api + internal db); folded in docker-compose.prod.yml; dev Postgres → docker-compose.dev.yml
- Dockerfile HEALTHCHECK (bash /dev/tcp) so deploy's docker-inspect Health.Status wait works
- Naming to convention: service api, container hamkadr_api/hamkadr_db, image mirror.soroushasadi.com/hamkadr/api:${API_TAG}
- Workflow rewritten to DrSousan pattern: ci build + deploy (rollback-tag before build, pg_dump backup, stop/rm/up, docker-inspect health-wait with crash detection, scoped image prune)
- environment: block with ${VAR:-default} substitution (no hard-failing env_file); HOST_PORT; .env excluded from image context
- nginx vhost + DEPLOY.md updated to match

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.dockerignore

@@ -1,5 +1,7 @@
 **/bin/
 **/obj/
+.env
+.env.*
 .git/
 .gitea/
 .vs/