Sticky selection after splitting Ghostty terminal

[frank-horus]

Steps to reproduce:

1. Open Ghostty, start Flow, and open a file.
2. Add a new Ghostty split.
3. Text select in the old split is now sticky. Escape deselects, but moving the mouse selects again, without click and drag.

Notes:

• Flow version: commit 4659d74 (latest as of writing)
• Ghostty version 1.3.1
• OS: Arch Linux
• Moving cursor with the arrow keys deselects and produces no new selection.
• Closing the new split doesn't undo this behavior.

Video:
https://github.com/user-attachments/assets/affe3e9a-4d92-4d47-ae1b-a99f455fc468