fix(actions): use per-step status in workflow job API response; add build workflow

ToActionWorkflowJob was calling ToActionsStatus(job.Status) for every
step, making each step reflect the whole job conclusion instead of its
own state. Replace the inline loop with the existing ToActionWorkflowStep
helper which correctly uses step.Status.

Add .gitea/workflows/build-push.yaml to build and push a Docker image to
Artifact Registry on push to this branch, enabling deployment to GKE.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/convert/convert.go

@@ -405,15 +405,7 @@ func ToActionWorkflowJob(ctx context.Context, repo *repo_model.Repository, task
 				runnerName = runner.Name
 			}
 			for i, step := range task.Steps {
-				stepStatus, stepConclusion := ToActionsStatus(job.Status)
-				steps = append(steps, &api.ActionWorkflowStep{
-					Name:        step.Name,
-					Number:      int64(i),
-					Status:      stepStatus,
-					Conclusion:  stepConclusion,
-					StartedAt:   step.Started.AsTime().UTC(),
-					CompletedAt: step.Stopped.AsTime().UTC(),
-				})
+				steps = append(steps, ToActionWorkflowStep(step, i))
 			}
 		}
 	}