What

Rejects redundant parentheses in condition expressions, matching DynamoDB behavior. ((a = :v)) and ((a = :v AND b = :v2)) are rejected, while (a = :v) and ((a = :v) AND (b = :v2)) are accepted.

Why

Closes #64

DynamoDB rejects condition expressions with redundant parentheses (parens that wrap a single already-parenthesized sub-expression). ExtendDB was accepting them.

Testing done

• Verified 8 parenthesization patterns against real DynamoDB
• Verified ExtendDB matches on all 8
• cargo test --workspace passes
• cargo clippy --all-targets -- -D warnings clean

Checklist

• I have read CONTRIBUTING.md
• All tests pass (cargo test --workspace)
• Code is formatted (cargo fmt --check)
• Clippy is clean (cargo clippy -- -W clippy::pedantic)
• I have added or updated tests for new functionality
• I have updated documentation if behavior changed
• Breaking changes are noted below (if any)

By submitting this pull request, I confirm that my contribution is made under
the terms of the Apache License 2.0 and I agree to the Developer Certificate of
Origin (DCO). See CONTRIBUTING.md for details.