Return PracticeTraceRefusal before dereferencing bindings or operator
results when structural type/shape checks fail. Guard seal_bound zip
against binding_result_count_mismatch. Add five refusal-without-exception
tests for malformed bound inputs.
Adds immutable practice-trace input, sealed-trace, and trace-refusal
records with deterministic identity-chain validation after the Contract/
Proof Replay Adapter, as authorized by ADR-0230.