Review transcript trim architecture

internal/stage/trim.go

@@ -329,14 +329,6 @@ func (trimStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*Stag
 			AbsolutePath: finalBoundsOutputPath,
 		},
 	}
-	if renderOutputPath != "" {
-		outputs = append(outputs, artifacts.Ref{
-			Kind:         "session_bounds_render",
-			Category:     "artifacts",
-			SessionID:    sessionID,
-			AbsolutePath: renderOutputPath,
-		})
-	}
 
 	return &StageResult{
 		Outputs:          outputs,

internal/stage/trim_test.go

@@ -112,6 +112,33 @@ func TestTrimStageRecordsLogAndGeneratedConfigRefs(t *testing.T) {
 	}
 }
 
+func TestTrimStageRenderDebugDiagnosticsAreNotStageOutputs(t *testing.T) {
+	env, m, scr, _ := setupTrimEnv(t)
+	paths := env.ArtifactStore.SessionPaths(m.SessionID)
+	writeFile(t, filepath.Join(paths.TranscriptsDir, "processed.json"), `{"segments":[{"id":1},{"id":2}]}`)
+	scr.BoundsBody = `{"trim_action":"trim","start_segment_id":1,"end_segment_id":2}`
+
+	cfg := *env.Config.Pipeline.Trim
+	cfg.Bounds.RenderDebug = true
+	env.Config.Pipeline.Trim = &cfg
+
+	result, err := (trimStage{}).Run(context.Background(), env, m)
+	if err != nil {
+		t.Fatalf("trim.Run() error = %v", err)
+	}
+	if len(scr.RenderRequests) != 1 {
+		t.Fatalf("scriptorium render requests = %d, want 1", len(scr.RenderRequests))
+	}
+	for _, out := range result.Outputs {
+		if out.Kind == "session_bounds_render" {
+			t.Fatalf("render diagnostics should not be stage outputs: %#v", result.Outputs)
+		}
+	}
+	if result.Metadata["bounds_render_output_path"] == nil {
+		t.Fatalf("bounds_render_output_path metadata missing: %#v", result.Metadata)
+	}
+}
+
 func TestTrimStageFailsWhenProcessedTranscriptMissing(t *testing.T) {
 	env, m, _, _ := setupTrimEnv(t)
 	_, err := (trimStage{}).Run(context.Background(), env, m)