Builds server/Dockerfile and pushes to this repo's Gitea Container
Registry (git.thumeit.com/tfaour/espresso-frame-server) on every push to
main that touches server/, tagged both latest and the commit SHA.
docker-compose.yml now sets both image: and build: -- deploy hosts can
docker compose pull to grab the CI-built image without needing this
repo's build context, while local dev can still docker compose build
against Dockerfile changes directly.