Add ordering for threads

tui_test.go

@@ -89,6 +89,52 @@ func TestSelectionSurvivesRefresh(t *testing.T) {
 	}
 }
 
+func TestDefaultThreadOrderingUsesStatusThenFile(t *testing.T) {
+	threads := []ReviewThread{
+		{ID: "resolved-outdated", Path: "a.go", IsResolved: true, IsOutdated: true},
+		{ID: "outdated", Path: "a.go", IsOutdated: true},
+		{ID: "current-z", Path: "z.go"},
+		{ID: "resolved", Path: "z.go", IsResolved: true},
+		{ID: "current-a", Path: "a.go"},
+	}
+	settings := defaultAppSettings()
+	sortReviewThreads(threads, settings.ThreadStatusOrder, settings.ThreadWithinStatus)
+	got := make([]string, len(threads))
+	for i, thread := range threads {
+		got[i] = thread.ID
+	}
+	want := []string{"current-a", "current-z", "outdated", "resolved-outdated", "resolved"}
+	if strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("thread order = %v, want %v", got, want)
+	}
+}
+
+func TestCustomThreadOrderingUsesOpeningTimestamp(t *testing.T) {
+	base := time.Date(2026, 7, 1, 12, 0, 0, 0, time.UTC)
+	threads := []ReviewThread{
+		{ID: "current", Path: "a.go", Comments: []ReviewComment{{CreatedAt: base}}},
+		{ID: "resolved-new", IsResolved: true, Path: "a.go", Comments: []ReviewComment{{CreatedAt: base.Add(2 * time.Hour)}}},
+		{ID: "outdated", IsOutdated: true, Path: "a.go", Comments: []ReviewComment{{CreatedAt: base.Add(time.Hour)}}},
+		{ID: "resolved-old", IsResolved: true, Path: "z.go", Comments: []ReviewComment{
+			{CreatedAt: base.Add(3 * time.Hour)},
+			{CreatedAt: base.Add(-time.Hour)},
+		}},
+	}
+	sortReviewThreads(
+		threads,
+		[]string{"resolved", "outdated", "unresolved"},
+		"timestamp",
+	)
+	got := make([]string, len(threads))
+	for i, thread := range threads {
+		got[i] = thread.ID
+	}
+	want := []string{"resolved-old", "resolved-new", "outdated", "current"}
+	if strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("thread order = %v, want %v", got, want)
+	}
+}
+
 func TestPaneFocusAndNavigation(t *testing.T) {
 	m := NewApp(nil, "o", "r", false, 50, 10*time.Second)
 	m.screen = threadScreen