refactor: add log to set_active_channel

src/aura_engine/core/mixer.py

@@ -123,6 +123,7 @@ class Mixer:
         """
         if channel:
             self.active_channel_name = channel.name
+            self.logger.info(SU.pink(f"Set active channel to '{channel}'"))
         else:
             self.active_channel_name = None
             self.logger.info(SU.pink("Reset active channel"))