stock_voice_not_deletable
Admin console: DELETE /admin/voices/{id} refuses the effective default - elect another default first. Every other voice deletes: an unpinned custom row is erased outright (0067), everything else becomes removed (0069) - hidden everywhere, restorable from the console's Removed section, pinned versions still speaking.
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_deletable",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}