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/platform/cloud/subscription/composables/useSubscription.ts

@@ -121,7 +121,11 @@ function useSubscriptionInternal() {
     void showSubscriptionRequiredDialog()
   }
 
-  const shouldWatchCancellation = (): boolean =>
+  /**
+   * Whether cloud subscription mode is enabled (cloud distribution with subscription_required config).
+   * Use to determine which UI to show (SubscriptionPanel vs LegacyCreditsPanel).
+   */
+  const isSubscriptionEnabled = (): boolean =>
     Boolean(isCloud && window.__CONFIG__?.subscription_required)
 
   const { startCancellationWatcher, stopCancellationWatcher } =
@@ -130,7 +134,7 @@ function useSubscriptionInternal() {
       isActiveSubscription: isSubscribedOrIsNotCloud,
       subscriptionStatus,
       telemetry,
-      shouldWatchCancellation
+      shouldWatchCancellation: isSubscriptionEnabled
     })
 
   const manageSubscription = async () => {
@@ -249,6 +253,9 @@ function useSubscriptionInternal() {
     subscriptionTierName,
     subscriptionStatus,
 
+    // Utilities
+    isSubscriptionEnabled,
+
     // Actions
     subscribe,
     fetchStatus,