feat: local/legacy settings dialog fix (#7990)

## Summary

Fix the issue where local/desktop users would top up and then see the
settings homepage dialog instead of the credits tab.

## Changes

- **What**: useSubscription.ts, TopUpCreditsDialogContent.vue,
SubscriptionRequiredDialogContent.vue
- **Breaking**: <!-- Any breaking changes (if none, remove this line)
-->
- **Dependencies**: <!-- New dependencies (if none, remove this line)
-->

## Screenshots (if applicable)

Showing this screen after topping up on local/desktop:
<img width="789" height="752" alt="image"
src="https://github.com/user-attachments/assets/ea92b30b-5c3b-412a-acbe-1b0893621e53"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7990-feat-local-legacy-settings-dialog-fix-2e76d73d365081c7b1e1f96a24745e7b)
by [Unito](https://www.unito.io)

src/components/dialog/content/TopUpCreditsDialogContent.vue

@@ -158,6 +158,7 @@ import Button from '@/components/ui/button/Button.vue'
 import FormattedNumberStepper from '@/components/ui/stepper/FormattedNumberStepper.vue'
 import { useFirebaseAuthActions } from '@/composables/auth/useFirebaseAuthActions'
 import { useExternalLink } from '@/composables/useExternalLink'
+import { useSubscription } from '@/platform/cloud/subscription/composables/useSubscription'
 import { useTelemetry } from '@/platform/telemetry'
 import { clearTopupTracking } from '@/platform/telemetry/topupTracker'
 import { useDialogService } from '@/services/dialogService'
@@ -175,6 +176,7 @@ const dialogService = useDialogService()
 const telemetry = useTelemetry()
 const toast = useToast()
 const { buildDocsUrl, docsPaths } = useExternalLink()
+const { isSubscriptionEnabled } = useSubscription()
 
 // Constants
 const PRESET_AMOUNTS = [10, 25, 50, 100]
@@ -252,9 +254,11 @@ async function handleBuy() {
     telemetry?.trackApiCreditTopupButtonPurchaseClicked(payAmount.value)
     await authActions.purchaseCredits(payAmount.value)
 
-    // Close top-up dialog (keep tracking) and open subscription panel to show updated credits
+    // Close top-up dialog (keep tracking) and open credits panel to show updated balance
     handleClose(false)
-    dialogService.showSettingsDialog('subscription')
+    dialogService.showSettingsDialog(
+      isSubscriptionEnabled() ? 'subscription' : 'credits'
+    )
   } catch (error) {
     console.error('Purchase failed:', error)