When the CLI displays a tree view of text, the colors are all not the same.

### Describe the bug

Describe the bug
When display results in a tree in the CLI, the last nodes leave color is incorrect.

● General-purpose(claude-opus-4.6) 🏗️ Neo: Create migration issues
│ Read history.md
│ │ .squad\agents\neo\history.md
│ └ L1:5 (4 lines read)
└ Edit history.md +27
└ .squad\agents\neo\history.md

In the screenshot, you will see that from "General-purpose" to just above edit, it is bright white, and the edit node is gray or off-white

Steps to reproduce the behavior
You just need to get a response that shows a tree.

### Affected version

GitHub Copilot CLI 1.0.34

### Steps to reproduce the behavior

You just need to get a response that shows a tree.

### Expected behavior

The colors should be the same

### Additional context

_No response_