TODO

• Drop the custom image build once the pinned Mobilizon release ships the PostgreSQL 18 migration fix (upstream merge request 1683, milestone 5.3.0). The build of files/Dockerfile fails on that release and names the migration that no longer needs the patch. Then delete files/Dockerfile, the build block in templates/compose.yml.j2, MOBILIZON_IMAGE and MOBILIZON_VERSION in vars/main.yml, and custom: true in meta/services.yml.