- Replace _is_meaningful_bracket_content with _is_grammar_bracket_content
that uses a whitelist of grammar particles (with, about/of, auf, etc.)
- Check IPA dictionary FIRST: if word has IPA, treat brackets as phonetic
- Strip orphan brackets (no word before them) that are garbled IPA
- Preserve correct IPA (contains Unicode IPA chars) and grammar info
- Fix variable name bug (result → text)
Fixes: break [breik] now correctly replaced, cross (with) preserved,
orphan [mais] and {'mani setva] stripped.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>