Commit ChonkLoad state after parsing

[AztecBot]

Summary

ChonkLoad updated the loaded circuit name before parsing bytecode, so a malformed load could leave the request with a new name and old parsed state. This change parses into a local temporary first, then commits the name, constraints, verification key, and kind together only after parsing succeeds.

Fix

• Move circuit_buf_to_mega_acir_format before any request.loaded_circuit_* mutation.
• Move the loaded circuit name and verification key into request state only after parsing succeeds.
• Add a regression where a failed second ChonkLoad leaves the previous loaded state intact.

Testing

• cmake --build --preset default --target bbapi_tests -j$(nproc)
• ctest --preset default -R 'BBApiInputValidation\.ChonkLoadFailureKeepsExistingLoadedState$' --output-on-failure

Issues

• Closes AztecProtocol/barretenberg-claude#2648 — make ChonkLoad request-state updates transactional after successful bytecode parsing.

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Created by claudebox · group: bb-audit-remediation