Round-3 review found two High issues, one of them a regression introduced by
round 2's own fix, plus ripple that no earlier round had looked for.

- Antigravity: remove the poll-loop cycle cap. Round 2 made it apply
  alongside the deadline instead of only when there was no deadline, so a
  task configuring turn_timeout: 1200 (960s of polling) was silently cut at
  120 * 5s = 600s. On the timeout=None path the two bounds expired at the same
  instant anyway, so the cap bounded nothing the wall-clock deadline did not.
  One clock now covers both cost modes.

- Orchestrator: shield and track the forced-kill grading pass.
  check_all_async offloads each criterion to asyncio.to_thread, which is not
  cancellable, so the 60s budget left a run_command criterion's subprocess
  running inside a sandbox that run()'s finally was about to move or rmtree.
  The budget still bounds how long we WAIT for a verdict; _await_pending_grade
  bounds when teardown may start. Mirrors SubAgentRunner, which documents this
  same hazard.

- EvaluationResult.forced_kill records the kill durably, alongside
  final_status like max_turns_exhausted. Once grading can turn a TIMEOUT into
  SUCCESS the status stops being a usable proxy for "blew its budget":
  reports_experiment._cost_complete returned True for rows that lost in-flight
  spend, the error_log_tail allowlist dropped the only evidence of the kill,
  and telemetry could not count breaches. All three now key off the flag, and
  run.json carries it.

- Bound the two new unbounded awaits (the pre-grading agent quiesce and the
  poll-budget cancel); both run on a connection already declared unresponsive,
  outside any watchdog. The quiesce also catches BaseException so a queued
  task.cancel landing there cannot skip the grading pass it protects.

- DRY: _evaluation_loop now calls _gate_passed instead of keeping a second
  hand-maintained copy of the FIRED-ONLY rule, and the two timeout handlers
  collapse into _handle_forced_kill. That brings run() back under ruff's
  ceiling, so its # noqa: PLR0915 and its CE022 _TARGETS entry are both gone.

- Docs: REPORT_SCHEMA.md gains the TIMEOUT-is-a-fallback gotcha and the
  ERROR -> TIMEOUT migration for turn timeouts; CLAUDE.md records forced_kill;
  smoke_task_timeout.yaml's comments no longer claim criteria are never
  evaluated on a timeout, which this change made false.

Co-Authored-By: Claude Opus 5 <[email protected]>