When kanban_complete rejects a created_cards list as hallucinated, the
task is intentionally left in-flight (the gate runs before the write
txn) so the worker can retry with a corrected list or pass
created_cards=[] to skip the check. The retry path already worked, but
the previous error wording read like a terminal failure and workers
were observed abandoning the run instead of trying again.
Spell out the recovery path explicitly in the tool_error response
("Your task is still in-flight ... Retry kanban_complete with ...") and
add regression coverage at both the kernel and tool layers so the
retry contract — and the wording the worker depends on to discover
it — is pinned.
Fixes#22923
Workers running slow models (e.g. kimi-k2.6) can spend longer than
DEFAULT_CLAIM_TTL_SECONDS inside a single tool-free LLM call, making
no tool calls and therefore not heartbeating. release_stale_claims
previously reclaimed these healthy workers, producing the
spawn-then-immediately-reclaim loop reported in #23025.
When a stale-by-TTL claim's host-local worker PID is still alive,
extend the claim (emit a claim_extended event) rather than killing
it. enforce_max_runtime / detect_crashed_workers remain the upper
bounds for genuinely wedged or dead workers. Reclaim events now also
record claim_expires, last_heartbeat_at, worker_pid, and host_local
so operators can see why a worker was killed.
Cherry-picked from PR #7747 with follow-up fixes:
- Narrowed suspend_all_active() to suspend_recently_active() — only
suspends sessions updated within the last 2 minutes (likely in-flight),
not all sessions which would unnecessarily reset idle users
- /stop with no running agent no longer suspends the session; only
actual force-stops mark the session for reset
konsisumer