Production-candidate Mithril nodes for IVC SNARK

## Why

The Mithril nodes have only exercised the IVC SNARK certification on a work in progress setup, with reduced protocol parameters and without continuous testing. Before the network can run the recursive certification in production, the nodes must sustain the full security parameters, protect the trust anchors of the scheme (genesis keys and circuit verification keys), and let a follower aggregator bootstrap and join at any time.

## What

Bring the Mithril nodes to a production-candidate state for the IVC SNARK: operate the certification with the full security parameters of the network, secure and manage its keys, support IVC follower aggregators joining the network at any time, and cover the SNARK path in the end-to-end tests.

Start by reviewing the current work-in-progress Mithril node setup and the existing IVC SNARK end-to-end test path. Trace how full network security parameters, genesis keys, and circuit verification keys are configured and managed. Done means production-level parameters and key protection, follower aggregators that can bootstrap and join at any time, and end-to-end coverage of the SNARK path.

Written by the indexing model from the issue text.