fix: improve doc link navigation and tree display

- Fix link resolution with proper relative/absolute path handling
- Improve link styling with underline decoration
- Hide leaf nodes from tree, only show directories
- Fix log file path for packaged app

docs/api/resources/resourcecache/add.md

@@ -0,0 +1,25 @@
+# ResourceCache::Add
+
+```cpp
+void Add(ResourceGUID guid, IResource* resource)
+```
+
+添加资源到缓存。将资源和 GUID 关联并记录内存大小、访问时间。线程安全。
+
+**参数：**
+- `guid` - 资源全局唯一标识符
+- `resource` - 资源指针
+
+**返回：** 无
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+cache.Add(guid, resource);
+```
+
+## 相关文档
+
+- [ResourceCache 总览](resourcecache.md) - 返回类总览