Kitty keyboard protocol not restored on Ctrl+C exit in Ghostty

Description

When exiting Claude Code via Ctrl+C in Ghostty terminal, the kitty keyboard protocol is not properly disabled/restored. This leaves the terminal in a broken state where subsequent keypresses are rendered as raw CSI u escape sequences in the prompt.

Reproduction

1. Open Ghostty terminal
2. Run claude
3. Press Ctrl+C to exit
4. Try typing anything — raw escape sequences appear instead of normal characters:

``
9;5u9;5u9;5u9;5u9;5ul9;5u22;5u
``

1. The prompt is unusable until reset is run

Expected behavior

Claude Code's SIGINT handler should pop/disable the kitty keyboard protocol mode (CSI < u) before the process exits, restoring the terminal to its previous keyboard state.

Workaround

Blindly type reset and press Enter to restore terminal state.

Environment

• Claude Code: 2.1.84
• Ghostty: 1.3.1 (stable)
• macOS (Darwin 25.3.0)
• Shell: zsh