## What changed
- Cover non-blocking credential probes when the file or secrets store is locked, including retaining only a matching prior credential snapshot and recovering after the lock is released.
- Extend the streamable HTTP OAuth round trip to verify that user turns continue during store contention, newly discovered servers recover after contention, and logged-out servers do not reuse authenticated connections.
- Cover reconciliation of authentication failures and effective `Authorization` headers.
GitOrigin-RevId: 8e377644001bd0be04dc9f79841080094d09d199