Login endpoint provides too much information when authentication fails with SAF provider

Describe the bug
Request:

http -a user:user post https://hostname.net:7554/gateway/api/v1/auth/login

Response - 401:

{
    "messages": [
        {
            "messageAction": "Provide correct user name.",
            "messageContent": "The platform returned error: ESRCH: The identity that was specified is not defined to the security product",
            "messageKey": "org.zowe.apiml.security.platform.errno.ESRCH",
            "messageNumber": "ZWEAT415E",
            "messageReason": "The user name does not exist in the system.",
            "messageType": "ERROR"
        }
    ]
}

Expected behavior
401 stating that the credentials are invalid

Version:
v2.10

Start by tracing the /gateway/api/v1/auth/login endpoint and the SAF-provider authentication failure handling. Inspect any existing login or authentication tests for the 401 response shape. Done means failed authentication returns only a generic invalid-credentials message rather than exposing the provider's identity or ESRCH details.