stock_voice_not_found
Admin console: no stock-voice catalog row has that id - neither in the deploy's seed YAML (inference/tts/voices.yaml) nor among admin-created voices (migration 0066's overlay).
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_not_found",
"title": "…",
"status": 404,
"detail": "…",
"instance": "/v1/…"
}