Function getSubtreeByDepth

getSubtreeByDepth<T extends Record<string, any>, K extends string = "children">(
    tree: T[],
    maxDepth: number,
    childrenKey?: K,
    currentDepth?: number,
): T[]
根据最大深度获取子树 / Get subtree by maximum depth

该函数递归遍历树形结构，返回一个不超过指定深度的新树。 / This function recursively traverses a tree structure and returns a new tree with depth not exceeding the specified maximum.
Type Parameters
- T extends Record<string, any>
  树节点的类型，必须是一个对象 / The type of tree node, must be an object
- K extends string = "children"
Parameters
- tree: T[]
  树形结构的数组 / Array of tree structure
- maxDepth: number
  最大深度（从0开始计数） / Maximum depth (counting from 0)
- OptionalchildrenKey: K = ...
  子节点属性名 / Children property name
- OptionalcurrentDepth: number = 0
  当前深度（内部递归使用） / Current depth (used internally for recursion)
Returns T[]
- 处理后的子树数组 / Processed subtree array
Example
```
// 示例树结构 / Example tree structure
const tree = [
  {
    id: 1,
    children: [
      { id: 2, children: [{ id: 3 }] }
    ]
  }
];

// 获取深度为1的子树 / Get subtree with depth 1
const result = getSubtreeByDepth(tree, 1);
// 结果: [{ id: 1, children: [{ id: 2 }] }]
```
- Defined in src/tree.ts:128