Delete ListDetail.tsx/.css (no importers after Task 3 rewrote ListsView),
remove SearchFilterResult interface and filterListTreeBySearch function + its
6 tests from listTree.test.ts, and replace invented CSS var names with literal
fallbacks in MoveListModal.css with the project's real theme variables.
Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com