Event Subscription Grant

An EventSubscriptionGrant is the platform's record that a subscriber product has been approved to receive events from a particular topic. It pairs a subscriberSlug with a topicName and captures the approval through grantedBy, grantedAt, and a reason explaining why access was given. If access is later withdrawn, revokedAt and revokedBy record that. The subscriber, topic, and granter relations make the grant fully traceable, so the platform always knows which products may consume which channels and who authorized each subscription.