Enhanced scoring mechanism (instead of strict IoU >= 0.5 introduced for the demo)

[creativeessence]

• Add oversized-interval penalties
• Add proof-of-access checks
• Calculate IoU similarity checks

[IlyasFardaouix]

I think the issue might be related to the fact that the verify_signature function in epistula.py is only checking for a 60s drift in the timestamp, but it doesn't account for the potential delay in propagating the timestamp to the client. Have you considered adding a proof-of-access check to verify the client's access to the latest timestamp?

[creativeessence]

We already have proof-of-check included in our roadmap ✅