fbcaed6816
- add note in DEV.md explaining basePath auto-deduction and breadcrumb slug convention - update README.md to document new `basePath` param in `registerNavItem` and detail active item/breadcrumb behavior - update navigation file listing in README.md to include new exported helpers - implement `getNavItemBasePath` and `findActiveNavContext` in navigation.js - use `basePath` in AdminSidebar to determine active item via longest-prefix match - use `basePath` in AdminTop to build breadcrumb with section, item, and action labels - expose new navigation helpers from admin index.js and registry.js