Fret Zealot — Web Bluetooth probe

What happens: a device chooser opens. Pick the Fret Zealot. Nothing lights up yet — this only opens the link and reports what it found.

Watch for: one red LED on the low E string, 5th fret. Nothing else lit.

Watch for: the D string, 7th fret cycling through five colors, about 1.5 s each — red, orange, yellow, purple, white. The names are printed in the log as each one fires.

Watch for: four LEDs lighting one at a time at the 5th fret, E then A then D then G, about a second apart — and each one staying lit as the next appears. All four should be on at the end.
This is the whole basis of the heavy-mode hot path: if lighting a new LED wipes the previous one, the additive design does not survive the browser.

Run this right after test 4, with all four LEDs still lit.
Watch for: the A and D LEDs going dark while E and G stay lit — with no flash, blink, or full-board wipe in between.

Watch for: the board clearing, then the four open-string LEDs at the nut lighting one at a time and all staying lit.
Fret 0 has its own history on this hardware, so it gets its own test.

This is the real test. Notes change at song speed (0.75 s tick, the heavy-mode cadence) with a full CLEAR flush every 30 s, exactly like ledsync.
Watch for: a steady walking pattern up and down the neck that never freezes, stutters, or goes dark. At 30 s, 60 s, 90 s there is a brief flush — a single blink is fine, a board that stays dark or stops moving is a failure.
Keep an eye on the error and disconnect counters below; they should stay at zero.
On the Pixel, also test backgrounding: about a minute in, switch to another app for ~30 s, then come back. The LEDs will almost certainly pause while you are away — what matters is whether they resume on their own or the link is dead and needs a reconnect. Note which in the Fail box either way; this is information, not a pass/fail on its own.