Under the hood
OAuth token refresh lock now reports its "acquired" event later, closer to the actual read check
What
When Claude Code refreshes an OAuth (login) token, it briefly locks a file to coordinate with other processes. The tengu_oauth_token_refresh_lock_acquired telemetry event that marks this used to fire right after the lock file was acquired; it now fires later, immediately before the strict read-check that follows. The internal helper that acquires the lock was also swapped for a different one.
Why
This is an internal reordering of when a telemetry event fires relative to the lock's actual use, which affects how accurately the event reflects the state of the lock at the time it's recorded.