Problem: Push job used docker:27-cli override with explicit dind cert
mounting, but runner base changed to code.forgejo.org/forgejo/runner:6.
Alpine container couldn't access Debian runner's dind socket paths.
Fix:
- Remove container override, run on golang runner natively
- Install docker.io directly in push step (apt-get)
- Add docker image prune post-action to cleanup
This pattern matches riotpiao.com CI and works with current runner setup.