Round 4 of the live design session, plus the nine-press census.

DJF readout speaks Hz, not percent — and the numbers come from BootTidal's own
gDJF ranges (lpf: range 180 20000 over 2v; hpf: range 20 8000 over 2(v-.5)),
so what the OLED says is what the filter DOES. The zero mark animates: heart
frames at ~3 fps while a DJF rests in the detent (charset 0x1E is a heart).
Home screen line 3 is now "118 BPM" — "36 live" was a control count nobody
asked for, and PLN rightly mocked it.

The OLED GHOST (/tmp/lcxl3-oled-ghost.txt): the protocol has no display
readback, so nothing can pull the screen — instead the driver mirrors every
frame IT sends into a box-drawing the shell can read. What the ghost cannot
show is the firmware's own native value overlay, and that is the point: when
PLN's eyes see content the ghost does not have, the discrepancy itself is the
diagnosis. (That discrepancy is live: the native overlay still outdraws our
temporary text on every control move — an Opus worker is in the programmer's
reference hunting per-control display targets, the likely correct fix.)

Keep-alive: the round-3 overlay stamped _oled_up_at on every push, so after
the firmware's 1.2 s timeout our overlay was never re-summoned — one good
overlay per touch, then raw values forever. Now the bring-up re-fires every
0.9 s of continuous activity and stamps only when actually sent.

THE EDGE-BUTTON CENSUS (PLN pressed, the log answered): Solo/Arm is ONE key
(ch1 CC65, two press cycles for his presses 1+2), Mute/Select is ONE key
(CC66), the Novation logo is alive (CC104), Track </> are CC103/102, Page
up/down CC106/107. Authored as EDGE_BUTTONS in lcxl3.py; the driver now names
them in the log instead of counting them unmapped. No functions assigned yet —
the settled direction is Track = setlist cursor, Page = OLED pages, the two
verb keys = record-arm and panic, logo in reserve.