Handle AWS SDK Go v2 errors the canonical way — errors.As against typed/modeled errors and the smithy.APIError interface — and NEVER strings.Contains(err.Error(), "...") to silence or branch on an SDK error. String-matching error text breaks silently across SDK upgrades and, worse, masks a deeper bug: if a "silenced" error fires on every normal invocation, the API is being called in a context AWS does not support (e.g. AdminLinkProviderForUser in PreSignUp). Use when writing or reviewing any error-handling branch around an AWS SDK Go v2 call, especially one that treats an error as "idempotent / already exists / edge case OK."
