pub async fn public_key_for(user_id: Uuid) -> Result<Option<String>, DBError>Expand description
Fetches a user’s base64-PEM public verification key from the global users
directory. Used on the token VERIFY path, looked up by the (still-unverified)
sub claim — so the right key is fetched before the per-user DB is reachable.
Returns None if the user is unknown or has no key.
§Errors
DBError::Sqlx on a DB error.