[Session Keys, experimental] 500 error from https://permissioned-keys.com/

I understand Session Keys are experimental, but I was hoping to continue testing.

To reproduce, follow the [Session Keys guide](https://www.smartwallet.dev/guides/session-keys#session-keys), granting permissions, then clicking the "Click" button results in a 500 error returned from https://permissioned-keys.com/

Please let me know if I should report these issues elsewhere.

Start with the Session Keys guide and reproduce the 500 response after granting permissions and clicking the "Click" button. Then trace the Session Keys flow in this repository and determine whether the failure is handled here or by permissioned-keys.com. Done means identifying the failing component and restoring the documented test flow, if the external service is in scope.

Written by the indexing model from the issue text.