Ingest an applicant

Ingests an applicant from your platform and starts screening. The applicant's registry is resolved from `location_ref`, so you do not pass an organization — one call, one applicant, wherever they applied. **What happens next.** The applicant receives a heads-up SMS immediately and an AI screening call a few minutes later. Results land in the registry's CONFIRM portal, at the `portal_url` in the response. **Store two things:** `candidate_id` and `portal_url`. The first is the durable correlation key; the second is your "View Full Details" link. **Idempotency.** Re-submitting the same applicant returns the existing IDs with `deduped: true` and a `200`. It never conflicts and never creates a second application on the same location. Matching is by your `external_ref` first, then by phone number, then by email — so an applicant who reaches a registry through both your intake form and a job board resolves to one person, not two. **Consent governs contact.** `consent.contact` must be `true` for CONFIRM to text or call. Send `false` (or omit it) and the applicant is still created and visible in the portal, but no outreach happens and the response returns `screening: "skipped_no_consent"`. This is the TCPA boundary: we contact within minutes of ingest, so consent is not something to assume. **Unknown locations fail loudly.** A `location_ref` we don't recognise returns `404 unknown_location_ref` rather than dropping the applicant. The same request succeeds on retry once the location exists.