The job runs in node:20-bookworm which ships no docker binary
(run 21 died with 'Unable to locate executable file: docker').
Install static docker client + buildx, and fail fast with an
actionable error if the runner has not mounted the docker socket.
- ci: run build jobs on the runner's default linux-amd64 label
- deploy: pin apollo images to 0.3.6 (built+pushed by CI on this tag)
Same app code as v0.3.5; first release deployed via Gitea Actions
(build) + Argo CD (rollout) instead of manual build/import/helm.