fix: Configure Firebase Auth persistence to avoid iOS Safari IndexedDB issues

- Use VueFireAuthWithDependencies to set localStorage-first persistence order
- Prevents "Connection to Indexed Database server lost" errors on iOS Safari
- Remove obsolete persistence test since configuration moved to main.ts

Fixes CLOUD-FRONTEND-STAGING-2J

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: christian-byrne

tests-ui/tests/store/firebaseAuthStore.test.ts

@@ -148,13 +148,6 @@ describe('useFirebaseAuthStore', () => {
     expect(store.loading).toBe(false)
   })
 
-  it('should set persistence to local storage on initialization', () => {
-    expect(firebaseAuth.setPersistence).toHaveBeenCalledWith(
-      mockAuth,
-      firebaseAuth.browserLocalPersistence
-    )
-  })
-
   it('should properly clean up error state between operations', async () => {
     // First, cause an error
     const mockError = new Error('Invalid password')