With quickshell-git, qs kill blocks until the instance has fully
exited, so restarting no longer needs to resolve pids and wait for them
to die. Kill in a loop until none remain - each call takes the oldest,
and duplicates from stale sessions are the reason this script exists.
The timeout bounds a wedged shell that can't process the quit message:
its kill would otherwise report success after Qt's 30s wait gives up,
re-killing the same undead instance forever. The test mock now kills
real processes synchronously to match.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>