Expose login type and session age in SDK

[MatthiasMAigner]

Hi SumUp team,

currently the SDK does not expose whether a user logged in with email/password or via cached session.
It also doesn't provide the time of the last login or when the session expire.

Because SumUp sessions expire automatically after ~30 days, this leads to unexpected login issues in production – especially when using the SDK without visible user interaction.

Feature request:
Please consider exposing:

Whether the current login used cached credentials or not
When the last real login (with password) happened or when the session expires.
This would help avoid failed payments and allow us to prompt users to re-authenticate in time.

Thanks!