Helps explain WHY each spawn goes warm vs cold. The existing
`spawn mode=warm|cold` log only shows the outcome at the spawn point —
to count where warmth is being lost, we need to see:
- when a session_id is recorded (and for which key),
- what every lookup returns (key + Some/None),
- when remove_sessions_for_story prunes (which is currently the only
explicit cold-induction path beyond "first ever spawn").
After this lands a grep of "session_store" in the logs gives the full
warm-resume health picture: which (story,agent,model) triples have a
recorded session, which lookups are hitting it, and which prunes are
costing us a warm respawn.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The bug 882 abort-respawn safeguard caps consecutive crashes at 5 then
blocks the story — but the underlying stdio abort itself stays unfixed:
each respawn calls start_agent which reads session_store.json, finds the
prior session id, passes --resume to claude-code, and re-triggers the
same crash. Five identical respawns later, the story is blocked.
Now: when an abort+no-session exit triggers respawn, we first call
session_store::remove_sessions_for_story to drop every entry for the
story. The next spawn starts cold (no --resume), which avoids the
bloated stdio replay claude-code is choking on.
The function was already implemented but #[cfg(test)] only — promoted
to a non-test pub fn. Existing remove_sessions_for_story_cleans_up test
unchanged and still green.
Net effect: instead of "5 retries, then blocked", we get "1 abort, prune,
respawn cold, agent runs normally". The story can resume work without
losing its worktree state.