feat(KB-048): add collapsible list sections to dashboard

- Add section expansion state management with localStorage persistence
- Update section headers with chevron toggle controls
- Implement conditional task row rendering based on section state
- Add Expand All / Collapse All toolbar controls
- Add CSS styles for chevron rotation animation and section headers
- Add comprehensive tests for collapsible section behavior

.changeset/add-task-duplicate.md

@@ -0,0 +1,5 @@
+---
+"@dustinbyrne/kb": minor
+---
+
+Add `kb task duplicate` command to create a copy of any task in triage.