- Create internal/adapters/firebase/auth.go with Auth, noopAuth, NewAuthOrNoop
(renamed from FirebaseAuth, noopTokenVerifier, NewFirebaseAuthOrNoop)
- Reduce internal/auth/firebase.go to TokenVerifier interface only
- Remove PhotoSearcher interface from adapters/pexels (belongs to consumers)
- Update wire.go and wire_gen.go to use firebase.NewAuthOrNoop
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>