v0.2.4 — --save no longer drops author-added export conditions

Fixed

• --save silently dropped author-added export conditions from root package.json — The root write-back only handled one level of string values when rewriting exports to ./dist/ paths, so a nested condition object (e.g. a hand-authored browser: { types, import, require }) was discarded without warning. The rewrite now recurses through nested conditions (and fallback arrays), preserving custom conditions and their spec-significant order across the --save round-trip.