docs: fix naming conventions across threading, math, memory, core, and debug modules

threading/:
- Rename 19 camelCase method files to hyphenated names
- task-system: createtaskgroup→create-task-group, etc.
- tasksystemconfig: enabletaskprofiling→enable-task-profiling, etc.
- thread: getcurrentid→get-current-id, etc.
- task: addref→add-ref, getid→get-id, etc.

math/:
- Rename underscore operator files to hyphenated
- vector3: operator_add→operator-add, etc.
- matrix4: gettranslation→get-translation, etc.
- vector4: tovector3→to-vector3, constructor_vector3→constructor-vector3
- sphere: sphere_constructor→sphere-constructor, etc.

memory/:
- Remove duplicate memorymanager/ folder (kept manager/ which was correct)

core/:
- filewriter: Consolidate ctor-default.md and ctor-file.md into constructor.md
- Rename dtor.md→destructor.md

debug/:
- filelogsink: Rename construct.md→constructor.md, ~filelogsink.md→destructor.md

All overview pages updated with new file references.

docs/api/threading/task-system/create-task-group.md

@@ -0,0 +1,41 @@
+# TaskSystem::CreateTaskGroup
+
+```cpp
+TaskGroup* CreateTaskGroup()
+```
+
+创建一个任务组用于批量管理多个任务。
+
+**参数：** 无
+
+**返回：** `TaskGroup*` - 新创建的任务组指针
+
+**线程安全：** ✅ (内部使用 SpinLock 保护)
+
+**复杂度：** O(1)
+
+**注意：**
+- 任务组必须通过 DestroyTaskGroup 显式销毁。
+- 任务组的所有权归调用者，TaskSystem 不负责销毁。
+
+**示例：**
+
+```cpp
+TaskGroup* group = TaskSystem::Get().CreateTaskGroup();
+
+group->AddTask([]() { LoadTextures(); });
+group->AddTask([]() { LoadModels(); });
+group->AddTask([]() { LoadAudio(); });
+
+group->SetCompleteCallback([]() {
+    printf("All resources loaded!\n");
+});
+
+group->Wait();
+TaskSystem::Get().DestroyTaskGroup(group);
+```
+
+## 相关文档
+
+- [TaskSystem 总览](task-system.md) - 返回类总览
+- [DestroyTaskGroup](destroytaskgroup.md) - 销毁任务组