Settle the numpad layout: 25 keys, one encoder

Six by five. Arrows on the outer column, PgUp/PgDn beside them, no Num key.
The scroll wheel is dropped - no good physical implementation - which also
removes the pointing-device path from the firmware entirely, frees a USB
endpoint, and retires the detentless-EC11 sourcing risk. The freed 2u at the
top takes a single volume encoder with room for a full-size knob.

BOM: diodes and sockets 26 -> 25, encoders 2 -> 1.

Co-Authored-By: Claude Opus 5 <[email protected]>

docs/bom.csv

@@ -22,9 +22,8 @@ HALF,Split,D-ESD,1,ESD 5V bidirectional,PESD5V0S1BA,C2827694,SOD-323,Extended,0.
 HALF,Split,J3,1,3-pin header DNF,JST SH,-,-,Consigned,0.02,"*** DNF INSURANCE *** VCC/GND/DATA fallback if SBU proves flaky (bad cables). 3 pads cost nothing"
 HALF,Split,-,-,SBU1+SBU2 TIE,-,-,-,-,0.00,"Tie A8 and B8 together on the board. SBU is CROSSED in the cable, so this makes it orientation-proof and doubles the conductor"
 NUMPAD,DNF,J1/U3/R3/R4/R5,0,DO NOT POPULATE,-,-,-,-,0.00,"*** From the ALL block: numpad MCU has NO connector of its own. Its D+/D- route internally to hub downstream port 1. No connector = no ESD part and no CC resistors needed. Saves ~$0.19"
-NUMPAD,Matrix,D1-D26,26,1N4148W,1N4148W,C81598,SOD-123,Basic,0.011,"26 keys: 17 numpad + 9 nav"
-NUMPAD,Encoder,ENC1,1,EC11 detented,EC11L1525G01,C2991196,THT,Extended,1.27,"VOLUME - wants detents. THT: hand-solder or JLC THT surcharge"
-NUMPAD,Encoder,ENC2,1,EC11 detentless,verify variant,-,THT,Extended,1.27,"SCROLL - wants NO detents for hi-res scroll. Confirm detentless SKU"
+NUMPAD,Matrix,D1-D25,25,1N4148W,1N4148W,C81598,SOD-123,Basic,0.011,"25 keys: 16 numpad (no Num key) + 9 nav"
+NUMPAD,Encoder,ENC1,1,EC11 detented,EC11L1525G01,C2991196,THT,Extended,1.27,"VOLUME - detented, which is what a stock EC11 already is. Occupies a 2u cell so a full-size knob fits. THT: hand-solder or JLC THT surcharge"
 NUMPAD,Hub,U4,1,USB2.0 4-port hub,CH334R,C4154405,QSOP-16-150mil,Extended,0.50,"Ports: 1=own MCU (internal FS) 2=left half 3=right half 4=spare"
 NUMPAD,Hub,Y2,1,12MHz crystal,X322512MSB4SI,C9002,SMD3225-4P,Basic,0.101,"CH334 has built-in load caps - verify internal value vs this 20pF CL crystal; fit DNF cap pads"
 NUMPAD,Hub,C12-C14,3,100nF 0402,CL05B104KO5NNNC,C1525,0402,Basic,0.006,"hub decoupling"
@@ -37,6 +36,6 @@ NUMPAD,Hub,R8-R13,6,56k 0402,FRC0402F5602TS,C2906875,0402,Extended,0.0018,"Rp pu
 NUMPAD,SBU,-,-,SBU PASS-THROUGH,-,-,-,-,0.00,"*** Passive trace *** Tie SBU1+SBU2 on J5 (left half) and on J6 (right half), then connect the two nets together. Carries QMK split_common UART between the halves. Numpad MCU does NOT touch this net"
 NUMPAD,SBU,D-ESD2,2,ESD 5V bidirectional,PESD5V0S1BA,C2827694,SOD-323,Extended,0.036,"One per half-port SBU net"
 HALF,Switches,SW-,1,MX hotswap socket,CPG151101S11,C41430893,SMD 14.5x5.9mm,Extended,0.037,"One per key. BOTTOM SIDE. Alt: C49352235 (CPG151101S11-2)"
-NUMPAD,Switches,SW-,26,MX hotswap socket,CPG151101S11,C41430893,SMD 14.5x5.9mm,Extended,0.037,"One per key. BOTTOM SIDE"
+NUMPAD,Switches,SW-,25,MX hotswap socket,CPG151101S11,C41430893,SMD 14.5x5.9mm,Extended,0.037,"One per key. BOTTOM SIDE"
 NOTE,Assembly,-,-,SINGLE-SIDED,-,-,-,-,-,"Put ALL SMD on the BOTTOM: sockets, MCU, passives, diodes, and any reverse-mount SK6812MINI-E. Top face bare except switch holes. Keeps JLC to one assembly pass"
 NOTE,Mechanical,-,-,PLATE REQUIRED,-,-,-,-,-,"Hotswap needs a switch plate or socket pads tear off during switch insertion. FR4 plate = just another JLC board"