Function public_key_for 

pub async fn public_key_for(
    user_id: Uuid,
) -> Result<Option<TokenIdentity>, DBError>

Fetches a user’s base64-PEM public verification key from the global users directory, with the account’s current status. 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.