Limit romanization to CJK lyrics

[ChouChiu]

Summary

• restrict local romanization generation to Chinese, Japanese, and Korean lyrics
• stop generating transliterations for Cyrillic, Spanish, and other non-CJK text
• remove the unused uroman and whatlang dependencies and refresh license metadata
• add regression coverage for non-CJK lyrics

Why

The romanization feature previously fell back to a general transliterator and special-cased Spanish, so enabling it affected lyrics outside its intended CJK scope.

Impact

Non-CJK lyric lines now remain without generated romanization. Existing Chinese Pinyin/Jyutping, Japanese Romaji, and Korean romanization behavior is preserved.

Validation

• cargo fmt --all -- --check
• cargo clippy --locked --all-targets --all-features -- -D warnings
• cargo test --locked --all-targets --all-features
• cargo build --locked --release
• cargo docs

The UI was not exercised in a real layer-shell Wayland session because this change is confined to lyrics-domain behavior.