hwci: audition AMYboard World sketches over the SysEx control API (#1071)

Expand the AMYboard HW CI beyond the built-in reference tones: after the
tones, download real AMYboard World sketches (shorepine's acid_generator,
house_generator, universal_hair, woodpiano), push each onto the board over
the SysEx "write to sketch" flow (docs/amyboard/control_api.md), drive it
with a simple MIDI arpeggio, record it, and spectral-compare to a committed
reference. This covers far more of AMY than the tones — the drum-heavy
generators exercise the path PR #1067's drums regression broke, which the
tone-only test missed.

The World sketches are fetched with stdlib urllib (the Pi CI venv has no
requests) and transferred with proper AK flow control — a stdbuf -oL
`amidi -d` reader on the Pi / mido input callback on mac, one frame in
flight. Without it the larger sketches' chunked transfers overflow the
board's SysEx ring buffer and corrupt sketch.py, which self-heals to the
silent default; the generative sketches recorded as silence until this was
added. The random *_generator sketches still reproduce at ~0.98 spectral
similarity run-to-run (timbre is stable even when the notes aren't), so they
compare with the existing timing/phase-invariant avg-spectrum metric.

References captured on the bench against the rolling amyboard release and
listened-to before commit. Disable the suite with --no-flash's sibling
--no-world.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: bwhitman

.github/workflows/amyboard-hwci.yml

@@ -5,7 +5,10 @@ name: HW CI (AMYboard + Tulip)
 # spectral-compare the audio to a committed reference. The hardware analogue of
 # amy/test.py, for BOTH boards that share the bench:
 #   * AMYboard — driven over USB-MIDI + AMY zP sysex; firmware from the per-PR
-#     Vercel preview (amyboard-pr-<N>.vercel.app). See hwci.py.
+#     Vercel preview (amyboard-pr-<N>.vercel.app). Runs the built-in reference
+#     tones, then pushes real AMYboard World sketches (acid/house/universal_hair/
+#     woodpiano) onto the board over the SysEx control API and records each.
+#     See hwci.py + docs/amyboard/control_api.md.
 #   * Tulip (TULIP4_R11) — driven over the MicroPython serial REPL (no USB-MIDI);
 #     firmware from the 'tulip-firmware' artifact the preview workflow builds.
 #     See tulip_hwci.py.
@@ -200,6 +203,10 @@ jobs:
           if-no-files-found: warn
           path: |
             hwci/hwci_basic-recording.wav
+            hwci/acid_generator-recording.wav
+            hwci/house_generator-recording.wav
+            hwci/universal_hair-recording.wav
+            hwci/woodpiano-recording.wav
             hwci/hwci_basic-serial.log
             hwci/hwci-run.log
             hwci/tulip_basic-recording.wav
@@ -236,13 +243,13 @@ jobs:
               marker,
               ...head,
               '',
-              `**AMYboard** (USB-MIDI + AMY \`zP\` → audio): ${line(amyPass)}`,
+              `**AMYboard** (USB-MIDI + AMY \`zP\` → audio; built-in tones + AMYboard World sketches acid/house/universal_hair/woodpiano over the SysEx control API): ${line(amyPass)}`,
               '',
               `**Tulip** (TULIP4_R11; serial-REPL audio + WiFi screenshot): ${line(tulipPass)}`,
               '',
               `**[⬇️ Artifacts: recordings · screenshot · serial logs · run logs](${runUrl})**`,
               '',
-              '<sub>Self-hosted bench. Audio spectral-compared to `ref/hwci_basic.wav` + `ref/tulip_basic.wav`; Tulip screenshot pixel-compared to `ref/tulip_screenshot.png`. Both analog outs share one capture card, so the tests run sequentially.</sub>',
+              '<sub>Self-hosted bench. Audio spectral-compared to `ref/hwci_basic.wav`, the AMYboard World sketch refs (`ref/{acid_generator,house_generator,universal_hair,woodpiano}.wav`) + `ref/tulip_basic.wav`; Tulip screenshot pixel-compared to `ref/tulip_screenshot.png`. Both analog outs share one capture card, so the tests run sequentially.</sub>',
             ].join('\n');
             const { data: comments } = await github.rest.issues.listComments({ owner, repo, issue_number: pr });
             const existing = comments.find(c => c.body && c.body.includes(marker));