- fix Windows-only golangci-lint findings in `lp_windows.go` and process killer handle cleanup
- add a `lint-go-windows` target that runs golangci-lint with `GOOS=windows`
- include the Windows lint pass in `make lint` so Ubuntu CI covers `_windows.go` files
Reviewed-on: https://gitea.com/gitea/runner/pulls/1052
Reviewed-by: Zettat123 <39446+zettat123@noreply.gitea.com>
- Adds `runner.post_task_script` and `runner.post_task_script_timeout` (default `5m`) to run a host executable after each task’s built-in cleanup (post-steps, container teardown, bind-workdir removal).
- Stops task heartbeats via `Reporter.StopHeartbeats()` while the script runs so Gitea won’t assign overlapping work; the final task acknowledgement still happens in `reporter.Close()`.
- Script output goes to the runner process log; non-zero exits are warned only and do not change the job result.
- Documents lifecycle, offline behavior, timeouts, and Windows limits (`.ps1` not supported yet) in `docs/post-task-script.md`.
Reviewed-on: https://gitea.com/gitea/runner/pulls/1026
Reviewed-by: Zettat123 <39446+zettat123@noreply.gitea.com>
