Workspaces 3 create a workspace (#8221)

## Summary

Add workspace creation and management (create, edit, delete, leave,
switch workspaces).

  Follow-up PR will add invite and membership flow.

  ## Changes

  - Workspace CRUD dialogs
  - Workspace switcher popover in topbar
  - Workspace settings panel
  - Subscription panel for workspace context
  

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8221-Workspaces-3-create-a-workspace-2ef6d73d36508155975ffa6e315971ec)
by [Unito](https://www.unito.io)

---------

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

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

@@ -64,7 +64,7 @@ vi.mock('@/services/dialogService', () => ({
 
 vi.mock('@/stores/firebaseAuthStore', () => ({
   useFirebaseAuthStore: vi.fn(() => ({
-    getAuthHeader: mockGetAuthHeader
+    getFirebaseAuthHeader: mockGetAuthHeader
   })),
   FirebaseAuthStoreError: class extends Error {}
 }))