Preview.10 strengthens the local material loop: selected voice admission now grows below its selected passage; the material index shows every structural depth; lasso remains armed until Canvas pan is chosen; and local undo is paired atomically with IndexedDB so validated history survives reloads.\n\nVerification: npm run check (938 passed, 1 skipped) and npm run test:e2e (43 Chromium flows) passed.\n\nThis is a GitHub source prerelease only. The exact version is ignored by the connected Vercel build and does not promote matter.ptoq.io production.