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/math/aabb/intersects-obb.md

@@ -0,0 +1,24 @@
+# OBB::Intersects (OBB)
+
+```cpp
+bool Intersects(const OBB& other) const
+```
+
+检测两个 OBB 是否相交（使用 SAT 分离轴定理）。
+
+**参数：**
+- `other` - 另一个 OBB
+
+**返回：** `bool` - true 表示相交
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+OBB obbA = ...;
+OBB obbB = ...;
+if (obbA.Intersects(obbB)) {
+    // 两个有向包围盒相交
+}
+```