Update saved AI provider

{
  "managed": true,
  "id": "<string>",
  "label": "<string>",
  "provider": "openai",
  "model": "<string>",
  "baseURL": "<string>",
  "enabled": true,
  "isDefault": true,
  "testStatus": "<string>",
  "testError": "<string>",
  "apiKeyPreview": "<string>",
  "apiKeyFingerprint": "<string>",
  "lastTestedAt": "2026-08-10T12:00:00Z",
  "lastUsedAt": "2026-08-10T12:00:00Z",
  "createdAt": "2026-08-10T12:00:00Z",
  "updatedAt": "2026-08-10T12:00:00Z"
}

{
  "defined": true,
  "code": "BAD_REQUEST",
  "status": 400,
  "message": "That provider setup isn't valid. Check the base URL and try again.",
  "data": null
}

{
  "defined": true,
  "code": "FORBIDDEN",
  "status": 403,
  "message": "AI is set up by the server administrator and can't be changed here.",
  "data": null
}

{
  "defined": true,
  "code": "NOT_FOUND",
  "status": 404,
  "message": "This AI provider no longer exists. Reload and choose another provider.",
  "data": null
}

{
  "defined": true,
  "code": "PRECONDITION_FAILED",
  "status": 412,
  "message": "AI providers aren't available on this server. Ask the server administrator to set ENCRYPTION_SECRET.",
  "data": null
}

{
  "defined": true,
  "code": "<string>",
  "status": 1,
  "message": "<string>",
  "data": null
}