Harden initial framework skeleton

internal/manifest/manifest_test.go

@@ -34,6 +34,10 @@ func TestStageMarkHelpers(t *testing.T) {
 	if len(stage.Outputs) != 1 {
 		t.Fatalf("outputs len = %d, want 1", len(stage.Outputs))
 	}
+	outputs[0].LocalPath = "mutated.json"
+	if stage.Outputs[0].LocalPath != "transcripts/processed.json" {
+		t.Fatalf("stage outputs should be copied, got %#v", stage.Outputs)
+	}
 
 	failedAt := succeededAt.Add(1 * time.Minute)
 	m.MarkStageFailed("analyze", failedAt, "analyzer crashed")
@@ -64,3 +68,45 @@ func TestStageMarkHelpers(t *testing.T) {
 		t.Fatalf("error code = %q, want %q", skipped.Error.Code, "skipped")
 	}
 }
+
+func TestMarkStageRunningClearsPriorCompletionAndError(t *testing.T) {
+	m := New("2026-05-03", time.Date(2026, 5, 3, 10, 0, 0, 0, time.UTC))
+
+	failedAt := time.Date(2026, 5, 3, 10, 1, 0, 0, time.UTC)
+	m.MarkStageFailed("merge", failedAt, "boom")
+
+	runAt := failedAt.Add(1 * time.Minute)
+	m.MarkStageRunning("merge", runAt)
+
+	stage := m.Stages["merge"]
+	if stage == nil {
+		t.Fatal("missing stage record")
+	}
+	if stage.Status != StatusRunning {
+		t.Fatalf("status = %q, want %q", stage.Status, StatusRunning)
+	}
+	if stage.CompletedAt != nil {
+		t.Fatalf("completed_at = %v, want nil while running", stage.CompletedAt)
+	}
+	if stage.Error != nil {
+		t.Fatalf("error = %#v, want nil while running", stage.Error)
+	}
+}
+
+func TestMarkStageSucceededClearsError(t *testing.T) {
+	m := New("2026-05-03", time.Date(2026, 5, 3, 10, 0, 0, 0, time.UTC))
+
+	m.MarkStageFailed("analyze", time.Date(2026, 5, 3, 10, 1, 0, 0, time.UTC), "failed once")
+	m.MarkStageSucceeded("analyze", time.Date(2026, 5, 3, 10, 2, 0, 0, time.UTC), nil)
+
+	stage := m.Stages["analyze"]
+	if stage == nil {
+		t.Fatal("missing stage record")
+	}
+	if stage.Status != StatusSucceeded {
+		t.Fatalf("status = %q, want %q", stage.Status, StatusSucceeded)
+	}
+	if stage.Error != nil {
+		t.Fatalf("error = %#v, want nil on success", stage.Error)
+	}
+}