Send a prompt to a running session

Resolves a canonical session id or its public/tracker alias to one tenant-scoped session. Non-terminal input is durably queued on the session heartbeat rail; terminal retries use a durable admission receipt before reset/re-dispatch. A terminal generation is re-dispatched only when its original work type and provider-session resume identity are established from live or durable evidence; missing continuity returns a typed held 409 and creates no queue item. A caller-supplied idempotency key returns the exact current queued/in_flight/applied/dead_lettered active disposition or the original terminal receipt and conflicts on changed input. `in_flight` means claimed by the daemon but not acknowledged as applied; `delivered:true`/`deliveryTier:live` appears only after an exact applied ACK.

curl -X POST 'https://app.rensei.ai/api/public/sessions/string/prompt' \  -H 'Content-Type: application/json' \  -d '{  "prompt": "string"}'

{  "delivered": true,  "deliveryTier": "durable",  "disposition": "queued",  "idempotencyKey": "string",  "promptId": "string",  "sessionId": "string",  "status": "queued",  "sessionStatus": "queued"}