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/task_taskmanager_test.cpp

@@ -26,6 +26,42 @@ protected:
 private:
 	bool *ran_ = nullptr;
 };
+
+class FailingTask final : public olive::Task {
+public:
+	FailingTask()
+	{
+		SetTitle(QStringLiteral("FailingTask"));
+	}
+
+protected:
+	bool Run() override
+	{
+		SetError(QStringLiteral("expected failure"));
+		return false;
+	}
+};
+
+class ProgressTask final : public olive::Task {
+public:
+	explicit ProgressTask(int steps)
+		: steps_(steps)
+	{
+		SetTitle(QStringLiteral("ProgressTask"));
+	}
+
+protected:
+	bool Run() override
+	{
+		for (int i = 0; i <= steps_; ++i) {
+			emit ProgressChanged(static_cast<double>(i) / steps_);
+		}
+		return true;
+	}
+
+private:
+	int steps_ = 1;
+};
 }
 
 TEST(TaskManager, AddAndRunTask)
@@ -50,3 +86,83 @@ TEST(TaskManager, AddAndRunTask)
 	EXPECT_TRUE(ran);
 	olive::TaskManager::DestroyInstance();
 }
+
+TEST(TaskManager, FailedTaskEmitsTaskFailed)
+{
+	olive::TaskManager::CreateInstance();
+	olive::TaskManager *mgr = olive::TaskManager::instance();
+	ASSERT_NE(mgr, nullptr);
+
+	FailingTask *task = new FailingTask();
+
+	QEventLoop loop;
+	bool saw_failed = false;
+	QObject::connect(mgr, &olive::TaskManager::TaskFailed, &loop,
+					 [&loop, &saw_failed](olive::Task *) {
+						 saw_failed = true;
+						 loop.quit();
+					 });
+	QTimer::singleShot(5000, &loop, &QEventLoop::quit);
+
+	mgr->AddTask(task);
+	loop.exec();
+
+	EXPECT_TRUE(saw_failed);
+	EXPECT_FALSE(task->GetError().isEmpty());
+	olive::TaskManager::DestroyInstance();
+}
+
+TEST(TaskManager, ProgressSignalIsEmitted)
+{
+	olive::TaskManager::CreateInstance();
+	olive::TaskManager *mgr = olive::TaskManager::instance();
+	ASSERT_NE(mgr, nullptr);
+
+	ProgressTask *task = new ProgressTask(4);
+
+	QEventLoop loop;
+	QVector<double> progress;
+	QObject::connect(task, &olive::Task::ProgressChanged, &loop,
+					 [&progress](double p) { progress.append(p); });
+	QObject::connect(task, &olive::Task::Finished, &loop,
+					 [&loop](olive::Task *, bool) { loop.quit(); });
+	QTimer::singleShot(5000, &loop, &QEventLoop::quit);
+
+	mgr->AddTask(task);
+	loop.exec();
+
+	EXPECT_FALSE(progress.isEmpty());
+	EXPECT_GE(progress.last(), 0.99);
+	olive::TaskManager::DestroyInstance();
+}
+
+TEST(TaskManager, MultipleTasksComplete)
+{
+	olive::TaskManager::CreateInstance();
+	olive::TaskManager *mgr = olive::TaskManager::instance();
+	ASSERT_NE(mgr, nullptr);
+
+	bool ran1 = false;
+	bool ran2 = false;
+	DummyTask *task1 = new DummyTask(&ran1);
+	DummyTask *task2 = new DummyTask(&ran2);
+
+	QEventLoop loop;
+	int finished = 0;
+	auto on_finished = [&loop, &finished](olive::Task *, bool) {
+		if (++finished == 2) {
+			loop.quit();
+		}
+	};
+	QObject::connect(task1, &olive::Task::Finished, &loop, on_finished);
+	QObject::connect(task2, &olive::Task::Finished, &loop, on_finished);
+	QTimer::singleShot(5000, &loop, &QEventLoop::quit);
+
+	mgr->AddTask(task1);
+	mgr->AddTask(task2);
+	loop.exec();
+
+	EXPECT_TRUE(ran1);
+	EXPECT_TRUE(ran2);
+	olive::TaskManager::DestroyInstance();
+}