`agent.restart_drain_timeout` defaults to 0 and governed every class of
in-flight work at once. That default is deliberate for chat turns: the
gateway announces the restart to the user and pre-marks the session
resume_pending, so interrupting one is cheap and recoverable.
A cron run has neither property. Nobody is waiting on it, it is written
to jobs.json as a permanent failure, and a recurring job simply skips to
its next schedule. Sharing the chat budget meant `_drain_active_agents()`
short-circuited on `timeout <= 0` before entering the wait loop, so the
drain reported `drain took 0.00s, timed_out=True, cron_at_start=1,
cron_now=1` — it detected the job and killed it anyway.
Cron work now drains on its own deadline, `agent.cron_drain_timeout`
(default 30s, 0 opts out). The floor is clamped to the shutdown-watchdog
leash minus a teardown reserve, so the longer wait can never consume the
post-drain cleanup window: being SIGKILLed mid-cleanup would leave the
job wedged at `last_status=running`, strictly worse than the bug. Being
bounded also means a cron-triggered restart cannot deadlock on itself.
The `timeout <= 0` special case is gone — an expired deadline expresses
the legacy "interrupt immediately" behaviour, so `timed_out` is always
computed from real state instead of asserted up front. The drain-timeout
warning now reports the elapsed wait rather than the configured budget,
which is what made "timed out after 0.0s" so confusing in the report.
Chat-only shutdowns are unchanged: `restart_drain_timeout: 0` still
interrupts chat turns immediately.
Relates to #82161 (complements #82195, which removes the `hermes update`
self-deadlock that triggered the reported instance).
HexLab98