Add minimal quality-gated convergence

Promote the S07 external FastAPI chain from score-only acceptance to a minimal quality-gated flow with refusal detection, retry/fallback recovery, handoff quality checks, and a multi-round consensus gate before final convergence.

Constraint: The user asked to fix the documented shortcomings around score-only convergence, weak refusal scoring, and unqualified handoff evidence while continuing the minimal version.

Rejected: Replacing the whole coordinator with a production consensus runtime | the minimal fix keeps the existing task pool/convergence shape and adds scenario-level quality gates plus consensus evidence.

Confidence: high

Scope-risk: moderate

Directive: Future S07 runs must keep all_outputs_pass_quality_gate and multi_round_quality_consensus_accepts_chain as required checks before claiming PASS.

Tested: .venv/bin/python -B -m unittest tests.test_standard_scenarios; .venv/bin/python -u -B examples/run_continuous_reasoning_acceptance.py; .venv/bin/python -B examples/export_model_agnet_io_report.py; .venv/bin/python -B -m unittest discover -s tests; .venv/bin/python -B -m py_compile swarm_minimal/*.py examples/*.py tests/*.py; .venv/bin/python -u -B examples/run_academic_standard_evaluation.py; .venv/bin/python -B -m unittest tests.test_model_io_report_audit; git diff --check; docs secret pattern scan.

Not-tested: The combined run_standard_scenario_acceptance wrapper was not rerun after report export to avoid creating a newer live run that would make the exported latest-run report stale.

Co-authored-by: OmX <omx@oh-my-codex.dev>

README.md

@@ -10,12 +10,13 @@
 
 ```json
 {
-  "run_id": "7ba01d0cc4ad402793938835654fbca5",
+  "run_id": "37155251926d4165a7b7af68e8967f64",
   "target_repo": "fastapi/fastapi",
   "target_commit": "ecace740f3eaccb1aba152cf1de79477095c56f4",
   "completed_tasks": 7,
   "accepted_score": 1.0,
-  "check_count": 12,
+  "check_count": 14,
+  "quality_consensus_rounds": 2,
   "failed_checks": []
 }
 ```