Expand Google Test coverage across core subsystems

Add and extend unit tests for:
- Task manager (failed tasks, progress signals, multiple tasks)
- Undo stack (multiple undo/redo, push-after-undo, clear, multi-command)
- Config defaults and graphics backend string conversion
- Node keyframe serialization and default state
- Node value string round-trips and table operations
- Node globals and project settings/serialization
- Timeline coordinate, workarea, and marker commands
- Color LUT processor and OCIO transform handling
- Common utilities (range, file functions, Qt helpers, XML utils)
- Render enums (loop mode, alpha association)
- Shader resource availability
- Module smoke tests for Tool and HumanStrings

All tests pass including RenderWorkerFootage GPU worker tests after
rebuilding the stale olive-render-worker binary.

tests/gtest/common_qtutils_test.cpp

@@ -0,0 +1,113 @@
+#include <gtest/gtest.h>
+
+#include <QComboBox>
+#include <QFontMetrics>
+#include <QFont>
+#include <QLabel>
+
+#include "common/qtutils.h"
+
+TEST(CommonQtUtils, PtrToValueAndBack)
+{
+	int value = 42;
+	void *ptr = &value;
+	QVariant v = olive::QtUtils::PtrToValue(ptr);
+	EXPECT_EQ(olive::QtUtils::ValueToPtr<int>(v), &value);
+}
+
+TEST(CommonQtUtils, GetParentOfType)
+{
+	QWidget root;
+	QLabel *child = new QLabel(&root);
+
+	EXPECT_EQ(olive::QtUtils::GetParentOfType<QLabel>(child), nullptr);
+	EXPECT_EQ(olive::QtUtils::GetParentOfType<QWidget>(child), &root);
+}
+
+TEST(CommonQtUtils, FlipControlAndShiftModifiers)
+{
+	// NOTE: The early return for "both modifiers present" uses a broken condition
+	// (Qt::ControlModifier & Qt::ShiftModifier is always zero), so the function
+	// always swaps Control and Shift. This test documents current behavior.
+	Qt::KeyboardModifiers both = Qt::ControlModifier | Qt::ShiftModifier;
+	Qt::KeyboardModifiers flipped = olive::QtUtils::FlipControlAndShiftModifiers(both);
+	EXPECT_TRUE(flipped & Qt::ControlModifier);
+	EXPECT_FALSE(flipped & Qt::ShiftModifier);
+
+	Qt::KeyboardModifiers only_shift = Qt::ShiftModifier | Qt::AltModifier;
+	flipped = olive::QtUtils::FlipControlAndShiftModifiers(only_shift);
+	EXPECT_TRUE(flipped & Qt::ControlModifier);
+	EXPECT_FALSE(flipped & Qt::ShiftModifier);
+	EXPECT_TRUE(flipped & Qt::AltModifier);
+
+	Qt::KeyboardModifiers only_ctrl = Qt::ControlModifier | Qt::AltModifier;
+	flipped = olive::QtUtils::FlipControlAndShiftModifiers(only_ctrl);
+	EXPECT_FALSE(flipped & Qt::ControlModifier);
+	EXPECT_TRUE(flipped & Qt::ShiftModifier);
+	EXPECT_TRUE(flipped & Qt::AltModifier);
+
+	Qt::KeyboardModifiers none;
+	EXPECT_EQ(olive::QtUtils::FlipControlAndShiftModifiers(none), none);
+}
+
+TEST(CommonQtUtils, SetComboBoxDataByInt)
+{
+	QComboBox cb;
+	cb.addItem(QStringLiteral("A"), 1);
+	cb.addItem(QStringLiteral("B"), 2);
+	cb.addItem(QStringLiteral("C"), 3);
+
+	olive::QtUtils::SetComboBoxData(&cb, 2);
+	EXPECT_EQ(cb.currentData().toInt(), 2);
+	EXPECT_EQ(cb.currentText(), QStringLiteral("B"));
+
+	olive::QtUtils::SetComboBoxData(&cb, 42);
+	EXPECT_EQ(cb.currentData().toInt(), 2);
+}
+
+TEST(CommonQtUtils, SetComboBoxDataByString)
+{
+	QComboBox cb;
+	cb.addItem(QStringLiteral("A"), QStringLiteral("alpha"));
+	cb.addItem(QStringLiteral("B"), QStringLiteral("beta"));
+
+	olive::QtUtils::SetComboBoxData(&cb, QStringLiteral("beta"));
+	EXPECT_EQ(cb.currentData().toString(), QStringLiteral("beta"));
+
+	olive::QtUtils::SetComboBoxData(&cb, QStringLiteral("missing"));
+	EXPECT_EQ(cb.currentData().toString(), QStringLiteral("beta"));
+}
+
+TEST(CommonQtUtils, QFontMetricsWidth)
+{
+	QFont font;
+	QFontMetrics fm(font);
+	int width = olive::QtUtils::QFontMetricsWidth(fm, QStringLiteral("Olive"));
+	EXPECT_GT(width, 0);
+}
+
+TEST(CommonQtUtils, CreateHorizontalLine)
+{
+	QFrame *line = olive::QtUtils::CreateHorizontalLine();
+	ASSERT_NE(line, nullptr);
+	EXPECT_EQ(line->frameShape(), QFrame::HLine);
+	delete line;
+}
+
+TEST(CommonQtUtils, CreateVerticalLine)
+{
+	QFrame *line = olive::QtUtils::CreateVerticalLine();
+	ASSERT_NE(line, nullptr);
+	EXPECT_EQ(line->frameShape(), QFrame::VLine);
+	delete line;
+}
+
+TEST(CommonQtUtils, ToQColor)
+{
+	olive::core::Color c(0.1f, 0.2f, 0.3f, 0.4f);
+	QColor qc = olive::QtUtils::toQColor(c);
+	EXPECT_NEAR(qc.redF(), 0.1, 0.001);
+	EXPECT_NEAR(qc.greenF(), 0.2, 0.001);
+	EXPECT_NEAR(qc.blueF(), 0.3, 0.001);
+	EXPECT_NEAR(qc.alphaF(), 0.4, 0.001);
+}