POST /calls/schedule and auto-fills phoneNumber from the contact record, plus injects contact context (name, tags, last interaction) so the agent knows who it's calling. The resulting Call is linked to the contact — shows up in their timeline, counts toward lifecycle stats. Agent must be isActive and owned by the caller; contact must have a valid E.164 phone.curl --location '/users/me/contacts//schedule-call' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '{
"goal": "string",
"scheduledAt": "string",
"agentId": "string",
"firstMessage": "string",
"additionalContext": "string"
}'