Use when migrating Docusaurus projects from v2 to v3 — upgrade @docusaurus/React/MDX/prism dependencies, rewrite MDX v1 syntax to v3 (escape bare { and <, fix autolinks), swap @tsconfig/docusaurus for @docusaurus/tsconfig, update Prism imports, and resolve React 18 breaking changes. Triggers on tasks involving MDX v1 to v3 migration, Docusaurus dependency updates, React 18 compatibility, or v2/v3 breaking changes.