React 19 Concurrent Patterns React 19 introduced new APIs that complement the migration work. This skill covers two concerns: 1. Preserve existing React 18 concurrent patterns that must not be broken during migration 2. Adopt new React 19 APIs worth introducing after migration stabilizes Part 1 Preserve: React 18 Concurrent Patterns That Must Survive the Migration These patterns exist in React 18 codebases and must not be accidentally removed or broken: createRoot Already Migrated by the R18 Orchestra If the R18 orchestra already ran, → is done. Verify it's correct: useTransition No Migration…