feat: add CreatedAt field to ActionWorkflowRun API

- Add CreatedAt field to ActionWorkflowRun struct in modules/structs/repo_actions.go
- Set CreatedAt in ToActionWorkflowRun converter in services/convert/convert.go
- This provides the creation timestamp for workflow runs in the API response

Author: rossigee

modules/structs/repo_actions.go

@@ -123,6 +123,8 @@ type ActionWorkflowRun struct {
 	HeadRepository *Repository `json:"head_repository,omitempty"`
 	Conclusion     string      `json:"conclusion,omitempty"`
 	// swagger:strfmt date-time
+	CreatedAt time.Time `json:"created_at"`
+	// swagger:strfmt date-time
 	StartedAt time.Time `json:"started_at"`
 	// swagger:strfmt date-time
 	CompletedAt time.Time `json:"completed_at"`

services/convert/convert.go

@@ -258,6 +258,7 @@ func ToActionWorkflowRun(ctx context.Context, repo *repo_model.Repository, run *
 		URL:          fmt.Sprintf("%s/actions/runs/%d", repo.APIURL(), run.ID),
 		HTMLURL:      run.HTMLURL(),
 		RunNumber:    run.Index,
+		CreatedAt:    run.Created.AsLocalTime(),
 		StartedAt:    run.Started.AsLocalTime(),
 		CompletedAt:  run.Stopped.AsLocalTime(),
 		Event:        string(run.Event),