fix first online resevation

DOCKER.md

@@ -5,6 +5,7 @@ Three Docker environments are available:
 - `Dockerfile.dev` with `docker-compose.dev.yml`
 - `Dockerfile.test` with `docker-compose.test.yml`
 - `Dockerfile.production` with `docker-compose.production.yml`
+- `docker-compose.pgmanage.yml` for a standalone pgManage container
 
 ### Development
 
@@ -75,6 +76,17 @@ pgAdmin Postgres connection:
 - username: `postgres`
 - password: `password`
 
+### Standalone pgManage
+
+If you want a standalone Postgres management UI without starting the full development stack:
+
+```bash
+docker compose -f docker-compose.pgmanage.yml up -d
+```
+
+It publishes `http://localhost:8000` with a standard Docker port mapping and persists its data in the named Docker volume `pgmanage_data`.
+From inside the container, connect to the local Postgres service through `host.docker.internal:5432`.
+
 ### Test
 
 Use the test stack to run repeatable containerized verification: