v0.24.1 introduced `prctl(PR_SET_PDEATHSIG, SIGKILL)` in #1137 to kill Chrome
when the daemon dies. However, `PR_SET_PDEATHSIG` tracks the **thread** that
called `fork()`, not the process (`prctl(2)` documents this). Chrome is spawned
via `tokio::task::spawn_blocking`, whose threads are reaped after ~10 seconds of
idle time. When the blocking thread exits, the kernel sends SIGKILL to Chrome
even though the daemon is still alive.
Symptoms reported in #1157:
- `tab list` shows `about:blank` after a few seconds
- `snapshot` returns an empty page
- All Chrome processes exit ~9 seconds after launch
- Any workflow involving navigation or waiting breaks
The fix removes `PR_SET_PDEATHSIG` from the Chrome `pre_exec` hook. Orphan
cleanup is already handled by the process-group kill (`kill(-pgid, SIGKILL)`) in
`ChromeProcess::kill()`, which runs via daemon signal handlers, `close_notify`,
idle timeout, and `Drop`.
Fixes#1157
Chris Tate
eb15cc0894