[Juliusolsson05]

Summary

• recover the exact Codex rollout id from bounded, forwarded Responses proxy metadata
• prove filename and session metadata identity before using the existing lease and generation-bound tail
• fail closed for malformed, oversized, ambiguous, subagent, and non-portable zstd frames
• add recorded exact-identity, concurrency, packaging, and portable decoder contracts

Verification

• npm run test:contract
• npm run typecheck
• focused recorded proxy tests on Node 20.19, 22.12, and 24
• npm run test:package
• standalone-clone full suite: 15 files, 177 tests passed before the final decoder-only regression; final focused decoder suite: 7 tests passed

A final full run in the shared local checkout had four unrelated 5-second rollout-test timeouts under CPU contention. The changed tests and typecheck stayed green; CI is the final clean-environment gate.