- Add ConfirmDraftBody schema to shared types
- Implement GET /api/labs/drafts/:id (retrieves draft with extracted data)
- Implement POST /api/labs/drafts/:id/confirm (normalizes markers, inserts lab draw + biomarkers in transaction, marks draft confirmed)
- Implement POST /api/labs/drafts/:id/discard (marks draft discarded)
- Add comprehensive test suite with 3 new tests
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
