feat(actions): Add Actions API endpoints for workflow run management and logs (#35382)

Implements the missing REST API endpoints for Actions workflow run
management:

1. `POST /actions/runs/{run}/cancel` cancels a run and its jobs, `409`
when it already finished
1. `POST /actions/runs/{run}/approve` approves a run awaiting approval,
idempotent, `409` when it never awaited one
1. `GET /actions/runs/{run}/logs` downloads the latest attempt's job
logs as a zip archive

`ActionWorkflowRun` gains `created_at`, `updated_at` and the `jobs_url`,
`logs_url`, `artifacts_url`, `cancel_url` and `rerun_url` fields, and
now always emits `conclusion` and `head_branch`.

Cancellation is shared with the web handler in `services/actions`.

Fixes https://github.com/go-gitea/gitea/issues/35176
Fixes https://github.com/go-gitea/gitea/issues/36554

---------

Co-authored-by: Claude Sonnet 4.6 <claude-sonnet-4-6@anthropic.com>
Co-authored-by: OpenCode Agent <opencode@rossgolder.com>
Co-authored-by: Nicolas <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/convert/convert.go

@@ -293,7 +293,7 @@ func ToActionWorkflowRun(ctx context.Context, run *actions_model.ActionRun, atte
 		completedAt = attempt.Stopped.AsLocalTime()
 		triggerUser = attempt.TriggerUser
 		if attempt.Attempt > 1 {
-			url := fmt.Sprintf("%s/actions/runs/%d/attempts/%d", run.Repo.APIURL(ctx), run.ID, attempt.Attempt-1)
+			url := fmt.Sprintf("%s/attempts/%d", run.APIURL(ctx), attempt.Attempt-1)
 			previousAttemptURL = &url
 		}
 	}
@@ -305,13 +305,21 @@ func ToActionWorkflowRun(ctx context.Context, run *actions_model.ActionRun, atte
 		}
 	}
 
+	runURL := run.APIURL(ctx)
 	return &api.ActionWorkflowRun{
 		ID:                 run.ID,
-		URL:                fmt.Sprintf("%s/actions/runs/%d", run.Repo.APIURL(ctx), run.ID),
+		URL:                runURL,
 		PreviousAttemptURL: previousAttemptURL,
 		HTMLURL:            run.HTMLURL(ctx),
+		JobsURL:            runURL + "/jobs",
+		LogsURL:            runURL + "/logs",
+		ArtifactsURL:       runURL + "/artifacts",
+		CancelURL:          runURL + "/cancel",
+		RerunURL:           runURL + "/rerun",
 		RunNumber:          run.Index,
 		RunAttempt:         runAttempt,
+		CreatedAt:          run.Created.AsLocalTime(),
+		UpdatedAt:          run.Updated.AsLocalTime(),
 		StartedAt:          startedAt,
 		CompletedAt:        completedAt,
 		Event:              run.TriggerEvent,