feat: update subscription panel with tier-based design and improved UX (#7307)

Transforms the subscription credits panel from legacy design to
tier-based layout with Creator tier details, updated typography using
design system tokens, improved responsive credit breakdown layout, and
better subscription management flow. Updates credit formatting to remove
unnecessary decimals and Credits suffix, replaces external Stripe
billing portal with inline dialog, and reorganizes plan benefits section
with proper v-for structure matching Figma specifications.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7307-feat-update-subscription-panel-with-tier-based-design-and-improved-UX-2c56d73d365081ef8b63e262a6822c72)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>

src/platform/settings/composables/useSettingUI.ts

@@ -85,7 +85,7 @@ export function useSettingUI(
       children: []
     },
     component: defineAsyncComponent(
-      () => import('@/components/dialog/content/setting/CreditsPanel.vue')
+      () => import('@/components/dialog/content/setting/LegacyCreditsPanel.vue')
     )
   }