fix: improve sidebar layout with scrollable sections and bottom-pinned admin

- Applications section: maxHeight 50vh with scroll overflow
- Starred section: maxHeight 30vh with scroll overflow
- Admin section: pinned to bottom of sidebar via position="bottom"
- Update design-system to 0.1.54 (sidebar section maxHeight, position props)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/package.json

@@ -15,7 +15,7 @@
     "postinstall": "node -e \"const fs=require('fs');fs.mkdirSync('public',{recursive:true});fs.copyFileSync('node_modules/@cameleer/design-system/assets/cameleer-logo.svg','public/favicon.svg')\""
   },
   "dependencies": {
-    "@cameleer/design-system": "^0.1.52",
+    "@cameleer/design-system": "^0.1.54",
     "@tanstack/react-query": "^5.90.21",
     "js-yaml": "^4.1.1",
     "lucide-react": "^1.7.0",