Super Roots

This issue tracks the remaining work to ship an upgrade to prove withdrawals with super roots instead of output roots. This is not full interop, just proving single chains with a super root. Most work has been done as part of the interop project, this tracks some loose ends.

Start by reviewing the existing interop project changes and identifying the remaining loose ends for the super-root upgrade. Confirm the scope is limited to proving withdrawals for single chains, not full interop, and verify that the resulting flow uses super roots instead of output roots.

Written by the indexing model from the issue text.