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

packages/engine/package.json

@@ -27,8 +27,9 @@
   },
   "devDependencies": {
     "@types/node": "^25.5.0",
+    "@vitest/coverage-v8": "^3.1.0",
     "typescript": "^5.7.0",
-    "vitest": "^4.1.1"
+    "vitest": "^3.1.0"
   },
   "private": true
 }