fix: make clippy and typos checks pass

[tyreseluo]

Summary

This PR fixes current CI failures in main.yml for clippy and typos.

Changes

• Replaced clippy-reported patterns with idiomatic equivalents:
  • removed needless explicit lifetime in tr_key
  • replaced manual ASCII case folding comparisons with eq_ignore_ascii_case
  • simplified boolean logic using is_none_or
  • replaced map_or(true, ...) with is_none_or(...)
• Updated test string literals that were flagged by typos false positives, while keeping test intent unchanged.

Validation

• RUSTFLAGS='-D warnings' cargo clippy --workspace --all-features passed
• typos passed