Assistant inbound channel event

Messaging delivers a channel event to Assistant, which owns identity resolution and authorization. A 2xx response means the event is durably persisted; Messaging retries non-2xx and may deliver the same event_id more than once. content.type selects text, media, selection or unsupported; content.kind describes media or unsupported provider content. No sender identity or business context is inferred by Messaging.

POST /internal/assistant/v1/channel-events