fix(ci): repair agent-review runtime URL-response contract #2277

Correction — invalid RCA, no owner delta

The original issue attributed #2272 run 35346250239 / job 105603403419 to tests/test_agent_review_runtime_contract.py::test_required_github_api_get_validates_effective_response_url and a SimpleNamespace context-manager mismatch. Fresh exact-head inspection disproves that attribution.

At #2272 exact 5b9e8642361818769d58af6f4e17a6087c90f6ad, .github/workflows/agent-review-runtime-quality-ci.yml runs these seven files:

• tests/test_strix_evidence_binding.py
• tests/test_codeql_scan_dispatch_consumer_scope.py
• tests/test_codeql_scan_dispatch_dual_credential_negative.py
• tests/test_codeql_scan_dispatch_error_path_security.py
• tests/test_codeql_scan_dispatch_pipeline_settlement_contract.py
• tests/test_codeql_scan_dispatch_ref_provenance.py
• tests/test_codeql_scan_dispatch_scheduler_capacity.py

The alleged tests/test_agent_review_runtime_contract.py is not part of that job and is not present in the #2272 tree. Repository search also does not find the alleged required_github_api_get test/helper. The original failure name and exception therefore were not valid evidence and must not be used as an owner path.

A separate, independently verified current-head security finding does remain in #2272/#2269: authenticated urllib.request calls admit only the initial https://api.github.com URL but Python's default redirect handler can carry request headers to a cross-origin 30x target. That finding is already tracked in the open PR lanes and is not evidence for this issue.

This issue has no valid implementation/test delta after the RCA correction, so it is closed as not planned rather than kept as a permanent false blocker. The failing Agent Review Runtime Quality job must be re-attributed only from reproducible exact-head evidence; no GREEN or failure cause is transferred from this issue.