docs: update memory and threading API docs

docs/api/threading/task-group/get-progress.md

@@ -0,0 +1,50 @@
+# TaskGroup::GetProgress
+
+```cpp
+float GetProgress() const;
+```
+
+获取任务组的完成进度。
+
+**参数：** 无
+
+**返回：** 
+- `float` - 0.0 到 1.0 之间的进度值，0.0 表示没有任务或都没有完成，1.0 表示全部完成
+
+**线程安全：** ✅ 线程安全
+
+**示例：**
+
+```cpp
+#include "XCEngine/Threading/TaskGroup.h"
+#include "XCEngine/Threading/Task.h"
+#include <iostream>
+#include <chrono>
+
+using namespace XCEngine::Threading;
+
+int main() {
+    TaskGroup group;
+
+    for (int i = 0; i < 4; ++i) {
+        group.AddTask([i]() {
+            std::this_thread::sleep_for(std::chrono::milliseconds(100));
+        });
+    }
+
+    while (!group.IsComplete()) {
+        float progress = group.GetProgress();
+        std::cout << "Progress: " << (progress * 100) << "%\n";
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+
+    std::cout << "Final Progress: " << (group.GetProgress() * 100) << "%\n";
+
+    return 0;
+}
+```
+
+## 相关文档
+
+- [TaskGroup 总览](task-group.md) - 返回类总览
+- [IsComplete](is-complete.md) - 检查是否完成