Summary

• Extract shared quantifier_operator_kind helper from duplicate pattern-matching logic
• Simplify is_skippable_quantifier and is_star_or_plus_quantifier to use the helper
• Reduces code from 41 lines to 34 lines with clearer intent

This is a pure refactoring with no behavioral changes — both functions now consistently unwrap CapturedExpr (which was already the case in practice at all call sites).