Physical robot emotion expression through Bluetooth-connected Freenove Pico Robot using R2-D2 beeps and sounds. Use when agents need to express emotions, status updates, or personality during task execution. Trigger on (1) successful task completion (happy), (2) errors/blocked states (angry), (3) processing/calculating (think), (4) ambiguous requests (confused), or (5) streaming audio playback (stream_audio).