fix(CSidebarNav): CNavGroup behavior

Author: mrholek

src/components/nav/CNavGroup.ts

@@ -12,7 +12,7 @@ const CNavGroup = defineComponent({
      */
     visible: {
       type: Boolean,
-      default: false,
+      default: undefined,
       required: false,
     },
   },
@@ -127,7 +127,7 @@ const CNavGroup = defineComponent({
                         return h(vnode, {
                           onVisibleChange: (visible: boolean) =>
                             handleVisibleChange(visible, index),
-                          visible: isVisible(index),
+                          ...(visibleGroup.value && { visible: isVisible(index) }),
                         })
                       }
                       return vnode

src/components/sidebar/CSidebarNav.ts

@@ -29,7 +29,7 @@ const CSidebarNav = defineComponent({
             if (vnode.type.name === 'CNavGroup') {
               return h(vnode, {
                 onVisibleChange: (visible: boolean) => handleVisibleChange(visible, index),
-                visible: isVisible(index),
+                ...(visibleGroup.value && { visible: isVisible(index) }),
               })
             }
             return vnode