Add tests for LtsTimelineClassic Item, TimelineView, TimelineWidget, TimelineIndicator

- test_item.cpp: 3 tests for Item class
- test_timelineview.cpp: 3 tests for TimelineView class
- test_timelinewidget.cpp: 3 tests for TimelineWidget class
- test_timelineindicator.cpp: 3 tests for TimelineIndicator class

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

qt6-after/qt6-migrated-benchmark/tests/test_timelineindicator.cpp

@@ -0,0 +1,67 @@
+#include "Lts/Common/LtsTimelineClassic/TimelineIndicator.h"
+
+#include <QApplication>
+#include <gtest/gtest.h>
+
+namespace LtsTimelineClassic
+{
+
+class TimelineIndicatorTest : public ::testing::Test
+{
+  protected:
+    void SetUp() override
+    {
+        int argc = 1;
+        char* argv[] = {const_cast<char*>("test")};
+        qApp = new QApplication(argc, argv);
+    }
+
+    void TearDown() override
+    {
+        delete qApp;
+        qApp = nullptr;
+    }
+};
+
+TEST(TimelineIndicatorTest, ConstructorCreatesValidIndicator)
+{
+    QWidget parent;
+    TimelineIndicator indicator(&parent);
+    EXPECT_NO_THROW(indicator.update());
+}
+
+TEST(TimelineIndicatorTest, SlotZoomChangesIndex)
+{
+    QWidget parent;
+    TimelineIndicator indicator(&parent);
+
+    int initialIndex = indicator.m_cbZoomLevel->currentIndex();
+    indicator.slotZoom();
+
+    // Zoom out should decrease index (if not already at 0)
+    if (initialIndex > 0)
+    {
+        EXPECT_EQ(indicator.m_cbZoomLevel->currentIndex(), initialIndex - 1);
+    }
+    else
+    {
+        EXPECT_EQ(indicator.m_cbZoomLevel->currentIndex(), 0);
+    }
+}
+
+TEST(TimelineIndicatorTest, SlotUnzoomChangesIndex)
+{
+    QWidget parent;
+    TimelineIndicator indicator(&parent);
+
+    int initialIndex = indicator.m_cbZoomLevel->currentIndex();
+    int maxIndex = indicator.m_cbZoomLevel->count() - 1;
+
+    // Set to a lower index to allow unzoom
+    indicator.m_cbZoomLevel->setCurrentIndex(1);
+    indicator.slotUnzoom();
+
+    EXPECT_EQ(indicator.m_cbZoomLevel->currentIndex(), 2);
+}
+
+} // namespace LtsTimelineClassic