- Python (kitty/launch.py): Track editor PID via monitor_pid to capture
exit code when editor window closes. Send exit code as data in the DONE
message instead of sending no data.
- Go (tools/cmd/edit_in_kitty/main.go): Parse exit code from DONE message
data and use lp.Quit(exit_code) to exit with the editor's exit code.
- Go (tools/cmd/tool/confirm_and_run_shebang.go): Check exit code when
running edit-in-kitty as a subprocess; abort execution on editor failure.
