NativeChatStructuredSessionDelivery.test.tsx went over the 800-line lint
limit after main was merged. The eight tests for the automatic probe of an
unconfirmed message move unchanged to
NativeChatStructuredSessionDelivery.probe.test.tsx, which uses the shared
structured-session test harness for its mocks. The outbox seeding and probe
clock helpers move into that harness so both files share them.
The at-most-once reliability gate now lists the new file, with a fresh
evidence run.
Brennan Benson
b5ce0d643f