Add test for LtsTimelineClassic Range.h

- Added test_range.cpp with 3 tests for Range struct
- Tests cover default constructor, parameterized constructor, and copy constructor

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

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

@@ -0,0 +1,39 @@
+#include "Lts/Common/LtsTimelineClassic/Range.h"
+
+#include <gtest/gtest.h>
+
+namespace LtsTimelineClassic
+{
+
+class RangeTest : public ::testing::Test
+{
+  protected:
+    void SetUp() override {}
+
+    void TearDown() override {}
+};
+
+TEST(RangeTest, DefaultConstructorInitializesToZero)
+{
+    Range range;
+    EXPECT_EQ(range.start, 0);
+    EXPECT_EQ(range.end, 0);
+}
+
+TEST(RangeTest, ParameterizedConstructorSetsValues)
+{
+    Range range(100, 500);
+    EXPECT_EQ(range.start, 100);
+    EXPECT_EQ(range.end, 500);
+}
+
+TEST(RangeTest, CopyConstructorWorks)
+{
+    Range range1(100, 500);
+    Range range2(range1);
+
+    EXPECT_EQ(range2.start, 100);
+    EXPECT_EQ(range2.end, 500);
+}
+
+} // namespace LtsTimelineClassic