change credits icons and tooltips (conditional on feature flag) (#7276)

This PR changes the credits icons and tooltips based on state of the
`subscription_tiers_enabled` feature flag.

When the flag is enabled (or undefined -- for local), the dollar icon is
replaced with the lucide-component icon in UserCredit and node price
badges (Partner Nodes), and a new tooltip row appears in
CurrentUserPopover displaying "Credits have been unified" with a
detailed hover tooltip explaining the credit unification across Partner
Nodes and Cloud workflows.

<img width="539" height="535" alt="image"
src="https://github.com/user-attachments/assets/7e952f9b-0abb-4979-85b7-0eecdeaf808c"
/>

Related:

- https://github.com/Comfy-Org/ComfyUI_frontend/pull/6115 (borrows badge
implementation from this PR)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7276-change-credits-icons-and-tooltips-conditional-on-feature-flag-2c46d73d365081809a6afd5861018a15)
by [Unito](https://www.unito.io)

src/renderer/extensions/vueNodes/components/NodeHeader.vue

@@ -38,7 +38,16 @@
           </IconButton>
         </div>
 
-        <div v-if="isApiNode" class="icon-[lucide--dollar-sign] size-4" />
+        <div v-if="isSubgraphNode" class="icon-[comfy--workflow] size-4" />
+        <div
+          v-if="isApiNode"
+          :class="
+            flags.subscriptionTiersEnabled
+              ? 'icon-[lucide--component]'
+              : 'icon-[lucide--dollar-sign]'
+          "
+          class="size-4"
+        />
 
         <!-- Node Title -->
         <div
@@ -98,6 +107,7 @@ import IconButton from '@/components/button/IconButton.vue'
 import EditableText from '@/components/common/EditableText.vue'
 import type { VueNodeData } from '@/composables/graph/useGraphNodeManager'
 import { useErrorHandling } from '@/composables/useErrorHandling'
+import { useFeatureFlags } from '@/composables/useFeatureFlags'
 import { st } from '@/i18n'
 import { LGraphEventMode } from '@/lib/litegraph/src/litegraph'
 import { useSettingStore } from '@/platform/settings/settingStore'
@@ -128,6 +138,8 @@ const emit = defineEmits<{
   'enter-subgraph': []
 }>()
 
+const { flags } = useFeatureFlags()
+
 // Error boundary implementation
 const renderError = ref<string | null>(null)
 const { toastErrorHandler } = useErrorHandling()