Merge-time fix for #666. `recordHookEvent()` ran for every `stop`, the run
summary files a `stop` as a warning, and the Away digest lists warnings under
Needs Attention, so each keep-alive nudge added a row there and to the
session's Summary timeline. The hook route now skips the run summary while
`keepAliveReason` is set (the keep-alive turn's `stop` and `idle_prompt`).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>