chore: upgrade dependencies, restructure shared libs, and fix UI

- Upgrade Nx 22.1.1 → 22.6.3 and all patch/minor dependencies
- Restructure shared libs: move business logic from utils to service
- Consolidate shadcn-ui into ui lib with atomic design pattern
- Fix container centering for landing app (Tailwind v4 compatibility)
- Fix button styling by updating @source directive in globals.css
- Fix SiCss3 → SiCss rename in react-icons 5.6
- Fix duplicate useSession export conflict
- Remove dead code, comments, and unused files

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

libs/utils/src/react-router/file-based-routing.tsx

@@ -50,7 +50,6 @@ export function convertPagesToRoute(
         return 'loader' in result ? result.loader?.(args) : null;
       },
       async guard() {
-        // Permission checking removed - always allow access
         return true;
       },
     });