- Add GitHub-style Actions **job summaries** support (writes to `GITHUB_STEP_SUMMARY` / `workflow/SUMMARY.md`) and render them in the run UI.
- Gitea stores summaries internally (DB) and serves them in the run view payload.
- `act_runner` uploads the summary **only when Gitea advertises support** (`X-Gitea-Actions-Capabilities: job-summary`), and warns on upload failures without failing the job.
## Compatibility
- New Gitea + old runner: no upload → no summary shown (no behavior change)
- New runner + old Gitea: capability not advertised → runner skips upload (no behavior change)
## Issue
- Fixesgo-gitea/gitea#23721
Reviewed-on: https://gitea.com/gitea/runner/pulls/917
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: Zettat123 <39446+zettat123@noreply.gitea.com>