The test stood for a request with usage.Saw("codex"). Saw's record lasts
the process, which the gateway relies on (LastSeen answers from it before
a request is written to the log), so a second run started with a request
seconds old, newer than its prompt five minutes back, and found nothing
bypassed ("bypassed: <nil>", also on origin/main).
Drift reads LastSeen through a package variable the test replaces with its
own clock; production still reads usage.LastSeen. That Saw is LastSeen's
answer at once moves to usage's own TestSawIsLastSeen, which removes its
record afterwards.
-run 'TestDrift|TestSawIsLastSeen' -race -count=5 passes; before, -count=2
failed.