stock_voice_reference_missing
Admin console: no reference clip is stored for that voice. 404 auditioning it; 409 trying to flip a voice available before its reference exists - upload the WAV, let the voice node's sync stage it, then flip.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/stock_voice_reference_missing",
"title": "…",
"status": "…",
"detail": "…",
"instance": "/v1/…"
}