feat(client): Sub-problem #2 support

[clabby]

Overview

The interop fault proof specifies two distinct sub-problems:

1. Single-chain derivation + execution for optimistic block generation.
2. Message graph resolution, aggregating previous results.

This ticket tracks the implementation of sub-problem #2.

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This sub-problem consists of aggregating all optimistic blocks generated by sub-problem #1 into the MessageGraph introduced in #924, checking message validity, and finally crafting the verified super root for comparison with the claim.

If an optimistic block is found to be invalid, this sub-problem must re-execute it with deposits only, and then re-attempt message graph resolution.