## Description
Noticed this reading the terminal runner: when a `terminal_exec` command
times out we only `SIGTERM` the shell. The shell isn't spawned
`detached`, so anything it backgrounded (`server &`, `nohup`, a dev
server) gets reparented to init and keeps running — an orphan leak on
every timed-out command that backgrounded something.
Fix: spawn the shell `detached` and signal the whole process group
(negative PID) on timeout, SIGTERM → 5s → SIGKILL — same pattern as
`apps/stage-tamagotchi/scripts/desktop-overlay-live-window-smoke.ts`.
Falls back to a single-process kill, non-timeout path unchanged.
## Linked Issues
None — just something I noticed.
## Additional Context
Added a regression test (backgrounds a `sleep`, times out, asserts the
pid is gone) — fails on `main`, passes here. `moeru-lint` clean. Left
PTY teardown (`pty-runner.ts`) out on purpose: job control puts
background jobs in their own groups, needs session-wide cleanup — happy
to follow up.
Alan-Yu-2077
445b597041