fix: sidebar resizing (#1730)

Regression from #1717

Author: knudtty

packages/app/src/components/AppNav/AppNav.module.scss

@@ -54,6 +54,7 @@ $transition-slow: 0.2s ease;
   background: var(--color-bg-sidenav);
   overflow: hidden;
   transition: width 0.2s ease;
+  flex-shrink: 0;
 
   &Fixed {
     position: fixed;