Review round (#86412):
- the except-import fallback returned the RAW oversized value, re-opening
the exact macOS time_t overflow this fix prevents; it now fails closed
to a finite ~1-year cap matching agent.deadline.MAX_SAFE_TIMEOUT_S
- clamp engagement logs a WARNING so operators see the semantic change
- new tests: float-form oversized value (YAML 1e18), warning emission,
and the import-failure fail-closed path (blocked-import probe proving
the result stays Lock.acquire-safe)
Widen the salvaged gate-site clamp to the bug class. The gate min() from
the contributor PR capped the gate bound at 360s, which would break the
#79719 contract (gate must extend while a legitimate >360s approval
prompt is answerable) and left the sibling overflow sites live: the CLI
prompt thread.join, the gateway poll deadline, and human_wait_ceiling
all consume the same config value.
Clamp once in _get_approval_timeout() via agent.deadline.MAX_SAFE_TIMEOUT_S
(1 year - semantically unbounded, platform-safe). The gate keeps its
approvals.timeout-tracking behavior above 360s; 7 regression tests pin
lock-acquire/thread-join safety and the gate-extension contract.
Bilateral E2E: with approvals.timeout=1e20 in a real config.yaml, main
crashes every consumer with OverflowError; this branch survives all 5
probes.
kshitijk4poor