Closes#8202.
Root cause: stop() reclaimed tool-call bash/sleep children only at the
very end of the shutdown sequence — after a 60s drain, 5s interrupt
grace, and per-adapter disconnect. Under systemd (TimeoutStopSec bounded
by drain_timeout), that meant the cgroup SIGKILL escalation fired first,
and systemd reaped the bash/sleep children instead of us.
Fix:
- Extract tool-subprocess cleanup into a local helper
_kill_tool_subprocesses() in _stop_impl().
- Invoke it eagerly right after _interrupt_running_agents() on the
drain-timeout path, before adapter disconnect.
- Keep the existing catch-all call at the end for the graceful path
and defense in depth against mid-teardown respawns.
- Bump generated systemd unit TimeoutStopSec to drain_timeout + 30s
so cleanup + disconnect + DB close has headroom above the drain
budget, matching the 'subprocess timeout > TimeoutStopSec + margin'
rule from the skill.
Tests:
- New: test_gateway_stop_kills_tool_subprocesses_before_adapter_disconnect_on_timeout
asserts kill_all() runs before disconnect() when drain times out.
- New: test_gateway_stop_kills_tool_subprocesses_on_graceful_path
guards that the final catch-all still fires when drain succeeds
(regression guard against accidental removal during refactor).
- Updated: existing systemd unit generator tests expect TimeoutStopSec=90
(= 60s drain + 30s headroom) with explanatory comment.