TanStack Router (v1+) reference for code-based routing, loaders, search params, navigation, link composition, route guards, and integration patterns. Use when working with files under src/ that import from '@tanstack/react-router', when creating or modifying routes/route trees, when designing data-loading via route loaders or beforeLoad, when adding type-safe Links/useNavigate/useParams/useSearch, when configuring RouterProvider or createRouter, or whenever the user mentions "tanstack router", "route loader", "useParams", "useNavigate", "search params", "beforeLoad", or "code-based routes". Also triggers for migration questions from react-router or other routers.