Install pgAdmin 9.18 in its own virtualenv and run it under gunicorn on
port 5050 next to PostgreSQL and the bridge. On first start the
entrypoint creates the pgAdmin login (PGADMIN_DEFAULT_EMAIL, default
admin@example.com; PGADMIN_DEFAULT_PASSWORD, default POSTGRES_PASSWORD)
and registers the bundled PostgreSQL server. pgAdmin is optional
(PEO4C_PGADMIN=false) and a failure in it does not stop the container.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
