fix: move WorkspaceAuthGate to LayoutDefault for proper re-login hand… (#8381)

## Summary

- Move WorkspaceAuthGate from App.vue to LayoutDefault.vue so it only
wraps authenticated routes
- Change initialize() to run in onMounted() for proper Vue lifecycle
- Restore immediate: true in cloudRemoteConfig watcher as backup
- Gate now mounts fresh after login, fixing re-login feature flag issue

The root cause was a race condition: after logout + page reload, the
cloudRemoteConfig watcher could be set up after the user already logged
in, missing the isLoggedIn change and never calling /features endpoint.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8381-fix-move-WorkspaceAuthGate-to-LayoutDefault-for-proper-re-login-hand-2f66d73d36508182a3dec09a49214a00)
by [Unito](https://www.unito.io)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/components/auth/WorkspaceAuthGate.vue

@@ -24,7 +24,7 @@
 import { promiseTimeout, until } from '@vueuse/core'
 import { storeToRefs } from 'pinia'
 import ProgressSpinner from 'primevue/progressspinner'
-import { ref } from 'vue'
+import { onMounted, ref } from 'vue'
 
 import { useFeatureFlags } from '@/composables/useFeatureFlags'
 import { isCloud } from '@/platform/distribution/types'
@@ -120,7 +120,10 @@ async function initializeWorkspaceMode(): Promise<void> {
   }
 }
 
-// Start initialization immediately during component setup
-// (not in onMounted, so initialization starts before DOM is ready)
-void initialize()
+// Initialize on mount. This gate should be placed on the authenticated layout
+// (LayoutDefault) so it mounts fresh after login and unmounts on logout.
+// The router guard ensures only authenticated users reach this layout.
+onMounted(() => {
+  void initialize()
+})
 </script>