added product import and billing integration

lib/presentation/auth/providers/auth_controller.dart

@@ -126,7 +126,14 @@ class AuthController extends StateNotifier<AuthState> {
     );
   }
 
-  void signOut() => state = const Unauthenticated();
+  /// The next shift should only ever bill against what the back office
+  /// answers with, never a catalogue instance carried over from this
+  /// session — so the local product table is dropped before the session
+  /// itself is.
+  Future<void> signOut() async {
+    await _ref.read(localStoreProvider).clearCatalogue();
+    state = const Unauthenticated();
+  }
 
   void clearError() {
     if (state is AuthFailure) state = const Unauthenticated();