Document PusherSubscriber and PushHandler at the interface level, document the
PushProvider members that had none, and add the missing @param entries.
Notable points: getCurrentDistributor also returns null when the stored
distributor is no longer installed, rotateToken throws unless canRotateToken is
true, and handleInvalid records the payload in the push history for diagnosis.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Benoit Marty
13aad55af8