Move the `set-option ... status off` call inside the existing try/catch
so a failure (e.g. the 5-second tmux command timeout firing on a slow
host) triggers `kill-session` cleanup instead of leaving an orphaned
tmux session behind. Renames the surfaced error to
"Failed to configure or launch session" since the try block now covers
both configuration and the launch send-keys.
Adds a regression test that asserts kill-session is called when
set-option throws.
Addresses review feedback on #1711.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
fc9e4bfdd8