fix(quorum): add collect-evidence timeout controls

[scarmani]

Summary

• add explicit --reviewer-timeout and --overall-timeout controls to review-queue collect-evidence and scripts/collect_quorum_evidence.py
• fail closed with JSON diagnostics when reviewer orchestration hits the overall deadline
• keep partial timed-out runs prepare-only: no partial quorum posting, no fabricated evidence, no Tier 3/4 auto-posting

Validation

• PYTEST_DISABLE_PLUGIN_AUTOLOAD=1 timeout 240 /Users/armand/.pyenv/versions/3.11.11/bin/python -m pytest tests/swarm/test_quorum_evidence.py tests/cli/commands/test_review_queue.py -q
• timeout 240 pre-commit run --files scripts/collect_quorum_evidence.py aragora/swarm/quorum_evidence.py aragora/cli/commands/review_queue.py aragora/cli/parser.py tests/swarm/test_quorum_evidence.py tests/cli/commands/test_review_queue.py
• push hook: mypy on changed Aragora files passed

Notes

• Draft only. Do not retry fix(tier4): prove self-quorum settlement blocker #8488 evidence until this tooling fix is merged or otherwise available on the active branch.

[scarmani]

Grok independent model review

Reviewer: grok (xai) — independent adversarial model review via the Aragora Grok reviewer, grounded on the exact PR head.
Head: 262d9b1 (262d9b1), committed 2026-06-17T17:06:56Z.
PR: #8493.
Model family: grok

Verdict: PASS

• No blocking correctness, security or regression issues identified in the diff.
• New overall-timeout path uses isolated processes + careful pgid/terminate/kill sequencing and always fails closed (intentional); per-reviewer override scoping via ContextVar is correct and does not leak into env or other calls.
• Return code, JSON shape, apply gating and existing retry/evidence logic are preserved except for the documented timeout-fail case.
• Added validation, tests and harness updates cover the new surfaces.

dogfood: yes

[scarmani]

OpenAI independent model review

Reviewer: openai (openai) — independent adversarial model review via Codex CLI OpenAI harness, grounded on the exact PR head.
Head: 262d9b1 (262d9b1), committed 2026-06-17T17:06:56Z.
PR: #8493.
Model family: openai

Verdict: PASS

No blocking issues found in the reviewed diff.

• [P3] aragora/swarm/quorum_evidence.py:1674 overall timeout can be exceeded by up to _REVIEWER_CLEANUP_TIMEOUT per completed-but-lingering reviewer process during cleanup. This weakens the wall-clock guarantee, but fail-closed behavior and posting prevention are preserved.

dogfood: yes

[github-actions]

Aragora Code Review

Advisory-only review. No issues found.

[scarmani]

Closing this PR as a frozen queue-drain churner rather than continuing repair loops.

Reason: this branch has repeatedly cycled through the same collect-evidence timeout/quorum surface across many repair lanes and heads, and it still has no merge-quorum authorization at head f5d4f03ac74b9f7c6e1700c55d0cf2d7af1dd60b. Per the queue-drain anti-treadmill rule, another patch on this substrate abstraction is not progress. The branch is preserved; any remaining timeout work should restart from current main as a smaller, fresh design rather than extending this PR.