test: cover AVM accumulated-data tail padding

[AztecBot]

Summary

The public tx-base validator already rejects non-zero AVM accumulated-data cells past their claimed lengths, but the regression suite did not exercise those defensive checks. This adds targeted negative coverage for every AVM accumulated-data tail that the validator zero-padding guard protects.

Fix

• Add public tx-base negative tests for AVM note hashes, nullifiers, L2-to-L1 messages, public data writes, and public log payload tails.
• Assert each test fails with the corresponding zero-padding validation message.

Testing

• PATH=/home/aztec-dev/aztec-packages/noir/noir-repo/target/debug:$PATH nargo test --package rollup_lib avm_ --silence-warnings

Issues

• Closes AztecProtocol/aztec-claude#1612 — AVM accumulated-data tail padding lacks negative regression tests

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Created by claudebox · group: rollup-audit-remediation