docs: Fix containers module documentation discrepancies

- Array::SetAllocator: Remove reference to non-existent PoolAllocator class
- HashMap::SetAllocator: Remove reference to non-existent GetDefaultAllocator()
- HashMap::Copy/Move: Fix move constructor complexity (O(m_bucketCount), not O(1))
- HashMap::iterator: Remove C++20 structured bindings example
- String: Add missing links for operator+ and operator==/!=

docs/api/containers/hashmap/copy-move.md

@@ -14,7 +14,7 @@ HashMap(HashMap&& other) noexcept;
 
 **复杂度：**
 - 拷贝构造：O(m_bucketCount + other.m_size)
-- 移动构造：O(1)，直接接管源对象的内部资源
+- 移动构造：O(m_bucketCount)，移动构造需要遍历所有桶以重新建立桶的指针关系
 
 **示例：**
 

docs/api/containers/hashmap/iterator.md

@@ -27,16 +27,6 @@ for (auto it = map.begin(); it != map.end(); ++it) {
     std::cout << it->first << " -> " << it->second << std::endl;
 }
 // 输出顺序不确定，取决于哈希桶的内部布局
-
-// 范围 for 循环（需要 C++20 或手动实现 begin/end）
-for (auto& [key, value] : map) {
-    std::cout << key << " -> " << value << std::endl;
-}
-
-// 常量迭代器
-for (auto it = map.begin(); it != map.end(); ++it) {
-    std::cout << it->first << " -> " << it->second << std::endl;
-}
 ```
 
 ## 相关文档

docs/api/containers/hashmap/setallocator.md

@@ -18,8 +18,8 @@ void SetAllocator(Memory::IAllocator* allocator);
 ```cpp
 XCEngine::Containers::HashMap<int, const char*> map;
 
-auto customAllocator = XCEngine::Memory::GetDefaultAllocator();
-map.SetAllocator(customAllocator);
+// 设置自定义分配器（如果使用内存分配器接口）
+// map.SetAllocator(customAllocator);
 ```
 
 ## 相关文档