[backport cloud/1.38] Feat/workspaces 6 billing (#8713)

Backport of #8508 to `cloud/1.38`

Automatically created by manual backport (cherry-pick of
c5431de123).

Conflicts resolved:
-
`src/platform/cloud/subscription/composables/useSubscriptionCredits.test.ts`
— accepted PR version (uses `useBillingContext` mock instead of
pinia/firebase auth)
- `src/services/dialogService.ts` — merged: kept cloud/1.38 eager
imports for dialog components, replaced `TopUpCreditsDialogContent` with
Legacy/Workspace variants, replaced `useSubscription` with
`useBillingContext`, added workspace/legacy component selection in
`showTopUpCreditsDialog`; skipped lazy loader refactor (separate PR, not
part of #8508)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/platform/assets/components/UploadModelUpgradeModal.vue

@@ -12,13 +12,13 @@
 </template>
 
 <script setup lang="ts">
+import { useBillingContext } from '@/composables/billing/useBillingContext'
 import UploadModelUpgradeModalBody from '@/platform/assets/components/UploadModelUpgradeModalBody.vue'
 import UploadModelUpgradeModalFooter from '@/platform/assets/components/UploadModelUpgradeModalFooter.vue'
-import { useSubscription } from '@/platform/cloud/subscription/composables/useSubscription'
 import { useDialogStore } from '@/stores/dialogStore'
 
 const dialogStore = useDialogStore()
-const { showSubscriptionDialog } = useSubscription()
+const { showSubscriptionDialog } = useBillingContext()
 
 function handleClose() {
   dialogStore.closeDialog({ key: 'upload-model-upgrade' })