Introduce a named person at a health system.

Why this endpoint returns before the email is sent. Enrichment is a model call with a web search inside it, and the physician who just pressed a button should not watch a spinner for however long that takes. The row and its landing token are written synchronously, so the introduction exists and is attributable the moment this returns, and delivery is scheduled after.

The response does not disclose whether we already know this organization. Same rule as create_referral above: the message is the same either way, and the physician's own funnel reports the real outcome a request later.