fix AVR input swap

demo.py

@@ -133,3 +133,13 @@ class DemoController:
 
     def play_heos_input(self, key, input_id, source_key=None):
         return None
+
+    # -- the AVR: app.py calls these directly, same as the real Controller
+    def avr_inputs(self):
+        return self.avr.inputs()
+
+    def avr_current_input(self):
+        return self.avr.current_input()
+
+    def avr_select_input(self, code):
+        return self.avr.select_input(code)