No unmodified example has played through `audiodev` on a board

[bdbarnett]

piano.py is the one — it uses the ordinary audio_out path with no pump
knowledge in it — and it needs a finger on the screen, so it is a sitting with
a human at the bench.

From #123.

[bdbarnett]

examples/piano.py, byte for byte, on a LilyGO T-Embed S3 with the board config from PyDevices/pydevices#44 (2026-09-21). It rotates itself into 320×170 landscape, its board_peripherals.audio_out(latency="low") comes back pumped=True with no machine.I2S anywhere, four notes and a chord sounded, and the DMA clocked 16 001 frames/s against a 16 000 Hz wire.

Said plainly: nobody touched it. The board has an encoder and a button, no touchscreen and no keyboard, so the notes went in through the example's own on_pointer_down at its own key rectangles. Hearing it is #127.