fix: Expose pipeline errors in API response

- Add PipelineErrorResponse struct to handler
- Add Errors field to PipelineResponse struct
- Add mapPipelineErrors helper function
- Include errors in both ListPipelines and GetPipeline responses

Root cause of CI failures: Woodpecker trust level doesn't allow privileged mode
for docker steps. Errors were being returned by Woodpecker but not exposed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/handlers/infrastructure_pipelines.go

@@ -8,9 +8,17 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/domain"
 	"github.com/orchard9/rdev/pkg/api"
 )
 
+// PipelineErrorResponse is the JSON representation of a pipeline error.
+type PipelineErrorResponse struct {
+	Type      string `json:"type"`
+	Message   string `json:"message"`
+	IsWarning bool   `json:"is_warning"`
+}
+
 // PipelineResponse is the JSON representation of a CI pipeline.
 type PipelineResponse struct {
 	ID       int64                   `json:"id"`
@@ -23,6 +31,7 @@ type PipelineResponse struct {
 	Author   string                  `json:"author"`
 	Started  string                  `json:"started,omitempty"`
 	Finished string                  `json:"finished,omitempty"`
+	Errors   []PipelineErrorResponse `json:"errors,omitempty"`
 }
 
 // ListPipelines returns recent CI pipeline executions for a project.
@@ -61,6 +70,7 @@ func (h *InfrastructureHandler) ListPipelines(w http.ResponseWriter, r *http.Req
 			Author:   p.Author,
 			Started:  formatTime(p.Started),
 			Finished: formatTime(p.Finished),
+			Errors:   mapPipelineErrors(p.Errors),
 		}
 	}
 
@@ -108,6 +118,7 @@ func (h *InfrastructureHandler) GetPipeline(w http.ResponseWriter, r *http.Reque
 		Author:   p.Author,
 		Started:  formatTime(p.Started),
 		Finished: formatTime(p.Finished),
+		Errors:   mapPipelineErrors(p.Errors),
 	})
 }
 
@@ -118,3 +129,19 @@ func formatTime(t time.Time) string {
 	}
 	return t.Format(time.RFC3339)
 }
+
+// mapPipelineErrors converts domain pipeline errors to response format.
+func mapPipelineErrors(errors []domain.CIPipelineError) []PipelineErrorResponse {
+	if len(errors) == 0 {
+		return nil
+	}
+	resp := make([]PipelineErrorResponse, len(errors))
+	for i, e := range errors {
+		resp[i] = PipelineErrorResponse{
+			Type:      e.Type,
+			Message:   e.Message,
+			IsWarning: e.IsWarning,
+		}
+	}
+	return resp
+}