fix(sidebar): use position fixed and transform for mobile sidebar (#3490)

* chore: bump nodejs version to 24

* fix(sidebar): use position fixed and transform for mobile sidebar

Use position: fixed to prevent horizontal scrolling on the mobile
bottom sheet, and replace style.top with transform: translateY() for
smooth drag performance. Cache element refs to avoid
document.querySelector on every drag frame. Apply the same position:
fixed fix to the notebook panel. Closes #3492

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

.github/workflows/pull-request.yml

@@ -49,7 +49,7 @@ jobs:
       - name: setup node
         uses: actions/setup-node@v6
         with:
-          node-version: 22
+          node-version: 24
           cache: pnpm
 
       - name: cache Next.js build

.github/workflows/release.yml

@@ -159,7 +159,7 @@ jobs:
       - name: setup node
         uses: actions/setup-node@v6
         with:
-          node-version: 22
+          node-version: 24
           cache: pnpm
 
       - name: setup Java (for Android build only)