Batch bit-op virtual claims in multipoint eval

[latifkasuli]

What changed

This is the next atomic follow-up after #191, #192, #194, and #204 for #185, which blocks #91.

This PR extends the multipoint-eval subprotocol so bit-op virtual claims can be batched into the final consistency check:

• Adds separate bit-op batching challenges to the mp-eval subclaim.
• Lets the prover include bit-op virtual MLEs in the precombined MLE.
• Lets the verifier include CPR-provided bit-op evals in the expected sum.
• Extends the final subclaim check to fold verifier-derived bit-op open evals into the final check.
• Keeps current protocol and bench call sites as no-op empty bit-op slices until the next PR materializes and derives real bit-op openings.

What is intentionally deferred

This PR does not yet materialize bit-op virtual MLEs in the full protocol prover, and it does not derive bit-op openings from lifted source openings in the protocol verifier. That is the next atomic PR. Existing UAIRs continue to use empty bit-op slots.

Validation

• Red/green: cargo test -p zinc-piop bit_op_virtual_opening_is_bound_in_subclaim
• cargo test -p zinc-piop multipoint_eval
• cargo check -p zinc-protocol
• .githooks/pre-push