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>

deploy/nginx-hamkadr.ir.conf

@@ -5,14 +5,14 @@
 #   sudo nginx -t && sudo systemctl reload nginx
 #   sudo certbot --nginx -d hamkadr.ir -d www.hamkadr.ir   # adds the :443 server + HTTP→HTTPS redirect
 #
-# APP_PORT below MUST match APP_PORT in the Gitea ENV_FILE secret (default 8090).
+# The port below MUST match HOST_PORT in the Gitea ENV_FILE secret (default 8090).
 
 server {
     listen 80;
     listen [::]:80;
     server_name hamkadr.ir www.hamkadr.ir;
 
-    # The app binds 127.0.0.1:8090 (docker-compose.prod.yml) — never exposed publicly.
+    # The app binds 127.0.0.1:8090 (docker-compose.yml, service "api") — never exposed publicly.
     location / {
         proxy_pass http://127.0.0.1:8090;
         proxy_http_version 1.1;