feat(ui): redesign sidebar and fix disclaimer

- Redesign AppSidebar with collapsible groups ("Identity & Access", "System")
- Nest "Shared Data" under "Accounts" in sidebar
- Add collapsible UI component for sidebar nesting
- Fix LocalhostDisclaimer by moving it inside SidebarProvider
- Add roadmap entry for sidebar redesign

docs/project-roadmap.md

@@ -437,6 +437,16 @@ src/types/
    - Deployment pipelines with type checks
    - Infrastructure as Code with TypeScript
 
+#### Phase 4: UI Enhancements - Sidebar Redesign (v4.7.0)
+**Timeline**: 1-2 months (TBD)
+
+**Priorities**:
+1. **Sidebar Redesign Implementation**
+   - Implement new sidebar component with modern UI/UX principles.
+   - Ensure responsiveness across different screen sizes.
+   - Integrate with existing routing and navigation logic.
+   - Improve accessibility features for the sidebar.
+
 ### Technical Debt Resolution
 
 #### Immediate Priorities (v4.4.1)