- Group chunks by regulation_code before batching for better LLM context
- Add generation_strategy column (ungrouped=v1, document_grouped=v2)
- Add v1/v2 badge to control cards in frontend
- Add sort-by-source option with visual group headers
- Add frontend page tests (18 tests)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>