Return nodes on a tree diameter path

## Problem You are given an undirected tree with `n` nodes labeled `0..n-1` (connected, no cycles). The **diameter** of a tree is the longest simple path between any two nodes. Return the nodes (in order) along **one** diameter path (if multiple diameter paths exist, returning any one of them is acceptable). ## Input - Integer `n` (`2 <= n <= 2 * 10^5`) - List of `n - 1` edges `edges`, where each edge is a pair `[u, v]` with `0 <= u, v < n` ## Output - A list/array `path` containing the node labels along a longest path (diameter), from one endpoint to the other. ## Constraints - The input graph is guaranteed to be a tree. ## Example Input: - `n = 6` - `edges = [[0,1],[1,2],[1,3],[3,4],[4,5]]` One valid output: - `[2,1,3,4,5]` Explanation: the longest path has length 4 edges, from node `2` to node `5`.