Function mnemonic_reveal_handler 

pub async fn mnemonic_reveal_handler<E>(
    __arg0: State<UiState<DynGatewayApi<E>>>,
    _auth: UserAuth,
    __arg2: Form<RevealMnemonicForm>,
) -> impl IntoResponse
where
    E: Display + Send + Sync + 'static,

Handler for revealing the mnemonic (POST request with password). Verifies the password and returns the mnemonic if valid.