fix: staging badge shown in cloud settings panel (#7444)

## Summary

Fixes issue where settings panel on cloud was showing a "Staging" badge
because the badge's logic was being dictated by the buildtime config.
Adds the same pattern used everywhere else where, if cloud distribution,
use runtime config; otherwise, fallback to buildtime config. Allows
cloud to switch between staging and prod at runtime while local switches
at buildtime.

After fix:

<img width="2062" height="811" alt="image"
src="https://github.com/user-attachments/assets/e53547c5-3dcc-42ea-9e75-602fe7f855a2"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7444-fix-staging-badge-shown-in-cloud-settings-panel-2c86d73d36508154a788e8e2a6dd025a)
by [Unito](https://www.unito.io)

src/components/dialog/header/SettingDialogHeader.vue

@@ -15,9 +15,7 @@
 <script setup lang="ts">
 import Tag from 'primevue/tag'
 
-// Global variable from vite build defined in global.d.ts
-// eslint-disable-next-line no-undef
-const isStaging = !__USE_PROD_CONFIG__
+import { isStaging } from '@/config/staging'
 </script>
 
 <style scoped>