chore: change `isSidebarVisible` initial value and use immediate watcher in sidebar

src/client/theme-default/composables/inert.ts

@@ -3,7 +3,7 @@ import { computed, reactive } from 'vue'
 export const inertControls = reactive({
   isSidebarOpen: false,
   isScreenOpen: false,
-  isSidebarVisible: true
+  isSidebarVisible: false
 })
 
 export const inertState = reactive({

src/client/theme-default/composables/sidebar.ts

@@ -83,7 +83,8 @@ export function useSidebar() {
         inertControls.isSidebarOpen = false
         inertControls.isSidebarVisible = sb && mq
       }
-    }
+    },
+    { immediate: true }
   )
 
   const sidebarGroups = computed(() => {