Gitea Actions doesn't support upload/download-artifact v4.
Reverted to two-job approach (git clone + docker build).
Added BuildKit cache mount (--mount=type=cache,target=/root/.m2)
to Dockerfile so Maven deps persist across Docker builds on the
same runner. First build downloads, subsequent builds are cached.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
