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/views/layouts/LayoutDefault.vue

@@ -1,11 +1,15 @@
 <template>
-  <main class="relative h-full w-full overflow-hidden">
-    <router-view />
-  </main>
+  <WorkspaceAuthGate>
+    <main class="relative h-full w-full overflow-hidden">
+      <router-view />
+    </main>
+  </WorkspaceAuthGate>
 </template>
 
 <script setup lang="ts">
 import { useFavicon } from '@vueuse/core'
 
+import WorkspaceAuthGate from '@/components/auth/WorkspaceAuthGate.vue'
+
 useFavicon('/assets/favicon.ico')
 </script>