Initial commit: Arduino Uno Q USB Audio Synth project

- USB gadget (UAC1 + MIDI) with boot persistence
- USB host mode with auto-detection
- Pure Data synth patch with ALSA + UDP netreceive MIDI input
- MIDI rawmidi-to-UDP bridge (midi-bridge.py)
- LED matrix visualization (led-matrix-viz.py via arduino-router RPC)
- MCU sketch for LED matrix control (Arduino_RouterBridge + ArduinoGraphics)
- Conftest/OPA Rego policy validation suite for .pd files
- gen_synth_pd.py: programmatic .pd file generator
- System services: midi-bridge, led-matrix-viz, pd-synth-auto, usb-role-detect
- Justfile with deploy, enable, diagnostic recipes
- Diagnostic script (diag.sh)

mise.toml

@@ -0,0 +1,14 @@
+# ═══════════════════════════════════════════════════════════
+#  Arduino Uno Q — USB Audio Synth
+#
+#  Tasks are managed by just (see justfile), not mise.
+#  Run `just --list` for available commands.
+# ═══════════════════════════════════════════════════════════
+
+[tools]
+just = "latest"
+
+[env]
+BOARD_HOST = "uno-q.local"
+BOARD_USER = "arduino"
+PD_PATCH = "synth.pd"