FP-5 evidence after the v11 Agent-only cutover

feature-preservation-contract.json is the frozen FP-5 historical contract from c84f448cbf1e98525745a260646b387d00e245fc (SHA-256 e02fb145c9470eb28ee7dd4d708806f014337ec8d4b9e999ccc9cb5008d691d1). Its owner approvals and transition node IDs record what was decided and measured on the compatibility facade. The v11 tree no longer collects all of those IDs: an exact file-level audit found 70 absent of 282 declared nodes, including engine-dependent differential oracles. Running this old contract on v11 is a failed historical gate, not a successful Agent parity check. It has not been rewritten to cite unrelated native assertions.

The v11 CI selector runs the full tests/evals suite and generated wheel journeys, then feature_preservation_v11_gate.py. The latter verifies the frozen contract hash, collects and executes its exact native quality sentinels, and writes fp5-v11-native.json. A green v11 quality verdict means those Agent assertions passed. The historical FP-5 verdict is superseded-historical-evidence; not-executed, and migration closure stays unknown. It does not establish compatibility-facade parity, migration admission, or engine retirement.

Remaining named quality unknowns are compatibility-facade parity after engine removal; native stream_typed for working_memory_recent_turns (the public Agent has no such method); and same-Agent multi-composition notice lifetime for domain_description_max_chars (the public Agent rejects duplicate prompting stages). Future work needs its own evidence and owner review before changing those verdicts.