fix(rhi): Fix RHI abstraction layer API docs per api-skill.md template

- Rename texture/dtor.md to destructor.md per template spec
- Remove duplicate non-hyphenated fence docs (getnativehandle.md, issignaled.md, getcompletedvalue.md)
- Fix template field issues:
  - swap-chain, command-queue: 类型 now uses 'class (abstract)'
  - sampler: 头文件 now uses full path 'XCEngine/RHI/RHISampler.h'
  - types: 类型 fixed from 'structs' to 'struct'
  - enums: 类型 fixed from 'enums' to 'enum class'
- Fix include paths in command-queue and pipeline-layout code examples
- Create missing constructor/destructor docs for 11 classes:
  buffer, texture, shader, device, command-list, command-queue,
  fence, sampler, swap-chain, pipeline-state, pipeline-layout
- Update class overview pages to include constructor/destructor entries

docs/api/rhi/buffer/buffer.md

@@ -16,6 +16,8 @@
 
 | 方法 | 描述 |
 |------|------|
+| [`RHIBuffer`](constructor.md) | 默认构造函数 |
+| [`~RHIBuffer`](destructor.md) | 虚析构函数 |
 | [`Map`](map.md) | 映射缓冲区到 CPU 可访问内存 |
 | [`Unmap`](unmap.md) | 取消映射 |
 | [`SetData`](set-data.md) | 设置缓冲区数据 |

docs/api/rhi/buffer/constructor.md

@@ -0,0 +1,28 @@
+# RHIBuffer::RHIBuffer
+
+```cpp
+RHIBuffer() = default;
+```
+
+默认构造函数，创建空的 RHIBuffer 对象。
+
+**参数：** 无
+
+**返回：** 无
+
+**线程安全：** ✅
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+// 创建空的缓冲区对象
+RHIBuffer* buffer = device->CreateBuffer(desc);
+// buffer 现在是一个有效的缓冲区引用
+```
+
+## 相关文档
+
+- [RHIBuffer 总览](buffer.md) - 返回类总览
+- [CreateBuffer](../device/create-buffer.md) - 创建设备

docs/api/rhi/buffer/destructor.md

@@ -0,0 +1,29 @@
+# RHIBuffer::~RHIBuffer
+
+```cpp
+virtual ~RHIBuffer() = default;
+```
+
+虚析构函数，确保派生类对象通过基类指针删除时能正确调用析构函数。
+
+**参数：** 无
+
+**返回：** 无
+
+**线程安全：** ✅
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+// 通过基类指针销毁缓冲区对象
+RHIBuffer* buffer = device->CreateBuffer(desc);
+// ... 使用 buffer ...
+delete buffer; // 自动调用派生类析构函数
+```
+
+## 相关文档
+
+- [RHIBuffer 总览](buffer.md) - 返回类总览
+- [Shutdown](shutdown.md) - 关闭缓冲区