Generates up to 5 query variants (synonyms + cross-language KR↔EN) so
later Notion API search can union over them. Permissive failure modes:
LLM error or non-JSON response falls back to [original] with stderr
warning. Dedupes and caps variants.
4 tests: variants list, dedup+cap, JSON-parse fallback, exception
fallback. 12 passing total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
