docs: Document stub/not-implemented methods in resources module

Fixed discrepancies between source code and documentation:
- AsyncLoader: Document Initialize() ignores workerThreadCount, Submit() doesn't do actual async loading, Update() is stub
- ResourceManager: Document UnloadUnused() and ReloadResource() are stubs
- ResourceCache: Document OnZeroRefCount() and Flush() are stubs
- ResourceDependencyGraph: Document TopologicalSort() returns empty (stub)
- ResourceFileSystem: Document GetResourceInfo() doesn't fill modifiedTime, EnumerateResources() is stub
- FileArchive: Document Enumerate() is stub
- ResourcePackageBuilder: Document AddDirectory() is stub
- ImportSettings: Document LoadFromJSON/SaveToJSON are stubs
- TextureImportSettings/MeshImportSettings: Document JSON methods are stubs
- TextureLoader/MeshLoader/MaterialLoader/ShaderLoader/AudioLoader: Document GetDefaultSettings() returns nullptr
- AudioLoader: Document ParseWAVData() is stub, Load() doesn't parse WAV headers
- ShaderLoader: Document DetectShaderType/ParseShaderSource are stubs
- MaterialLoader: Document ParseMaterialData() is stub
- Texture: Document Create() mipLevels=0 behavior, GenerateMipmaps() returns false
- Mesh: Document MeshLoader::Load() is example only
- IResourceLoader: Document GetDefaultSettings() returns nullptr for all loaders

docs/api/threading/task-group/wait.md

@@ -4,18 +4,19 @@
 void Wait()
 ```
 
+**注意：** 此方法当前为**空实现/桩代码**，不执行任何操作。
+
 阻塞当前线程，等待任务组中所有任务完成。
 
 **参数：** 无
 
 **返回：** 无
 
-**复杂度：** O(n)，n 为任务数量
+**复杂度：** N/A（空实现）
 
-**注意：** 
-- 如果任务组已被取消，此方法将立即返回。
-- **警告**：由于实现缺陷，`m_pendingCount` 计数器在任务完成后不会递减，导致 `Wait()` 在所有任务执行完毕后仍会永久阻塞。这是当前实现的已知问题。
-- 建议使用 `WaitFor()` 代替以避免永久阻塞。
+**当前状态：** 此方法为空实现，不执行任何操作。由于 `m_pendingCount` 计数器未正确更新，此方法永远无法正常运作。
+
+**建议：** 使用 `WaitFor()` 代替以避免永久阻塞。
 
 **示例：**
 
@@ -29,8 +30,12 @@ for (int i = 0; i < 10; ++i) {
 }
 
 printf("Waiting for all tasks...\n");
-group->Wait();
-printf("All tasks completed!\n");
+// 注意：Wait() 为空实现，建议使用 WaitFor()
+if (group->WaitFor(std::chrono::seconds(5))) {
+    printf("All tasks completed within 5 seconds\n");
+} else {
+    printf("Timeout! Tasks may not have completed\n");
+}
 
 TaskSystem::Get().DestroyTaskGroup(group);
 ```