Tighten workspace artifact path handling

internal/app/app_test.go

@@ -3346,15 +3346,22 @@ func plannedBatchNotificationReports(t *testing.T, cfg config.Config, batch Batc
 	if err != nil {
 		t.Fatalf("planBatchRun() error = %v", err)
 	}
-	reportDir := filepath.Join(t.TempDir(), "managed-reports")
+	store, err := state.NewFilesystemStore(cfg.Workspace)
+	if err != nil {
+		t.Fatalf("NewFilesystemStore() error = %v", err)
+	}
 	results := make([]BatchReportResult, 0, len(planned))
 	for _, item := range planned {
 		metadata := item.Resolved.Metadata()
+		paths, err := store.Paths(item.Resolved)
+		if err != nil {
+			t.Fatalf("Paths(%s) error = %v", item.Resolved.Definition.ID, err)
+		}
 		results = append(results, BatchReportResult{
 			ReportID:   item.Resolved.Definition.ID,
 			RunID:      metadata.RunID,
 			Status:     "succeeded",
-			ReportPath: filepath.Join(reportDir, string(item.Resolved.Definition.ID), metadata.RunID+".md"),
+			ReportPath: paths.RenderedReport,
 		})
 	}
 	return planned, results