Find unused code, unreferenced endpoints, orphaned React components, and unused dependencies across the backend and frontend — directly useful for the already-planned scratch/ to scripts/audit/ cleanup and general pre-baseline hygiene. Use when the user wants to identify safe-to-delete code before the clean git baseline milestone, asks what's actually unused in scratch/, or wants to confirm the 11 stub modules excluded from the OpenAPI surface are correctly isolated (not accidentally referenced elsewhere). This is Phase-1-relevant specifically because it directly serves the clean-baseline goal, unlike broader refactoring work.
