BOM: exclude J3 from BOM, verify part numbers against review requirements

The BOM was already fully populated (112/113 parts with MPN+LCSC) - this
audits it against the hardware-review requirements and closes the gaps:

- J3 (SP1 edge connector) set to in_bom=no: it is PCB gold fingers, not
  a purchasable part. Netlist-vs-BOM count check now differs by exactly
  this one deliberate exclusion.
- Crystals verified CL=12pF (Y1 C70565, Y2 C9006, both JLC Basic) -
  matches the 18pF load caps and W5100S Table 9. TODO item closed.
- 12V-rail caps verified >=25V (C3/C4 25V, C6 50V, C65 Lelon 25V SMD
  electrolytic); divider/REF/RSET resistors verified 1%.
- Noted: D2 LCSC C49383400 is the ElecSuper PUSB3AB6Z(ES) clone of the
  Nexperia part (same DFN-7 package, 0.15pF) - pin-compatible.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

hardware/re-bba-rb/TODO.md

@@ -113,9 +113,10 @@ W5100S reference schematic, and JLCPCB manufacturing limits. ERC/DRC: clean.
 
 - [ ] RSET_BG: datasheet says 12.3 kΩ 1 % (ref schematic: 12 k + 300 Ω);
       board has 12.4 k (~0.8 % off). Match if convenient.
-- [ ] Crystals Y1 (FTDI 12 MHz) and Y2 (W5100S 25 MHz): 18 pF load caps are
-      correct **only for CL ≈ 12 pF crystals** — pick parts accordingly
-      (W5100S Table 9 recommends CL = 12 pF).
+- [x] Crystals Y1/Y2 — VERIFIED 2026-07-17: the BOM parts are both CL = 12 pF
+      (Y1 YXC X322512MOB4SI / C70565, Y2 X322525MOB4SI / C9006, both JLC
+      Basic, ±10 ppm) — correct for the 18 pF load caps and the W5100S
+      Table 9 recommendation. No change needed.
 - [ ] 12 V-rail parts ≥ 25 V rating: C3, C4 (10 µF 0805), C6, C65 (100 µF
       electrolytic); D3 SMAJ12A already correct.
 - [ ] 1 % tolerance required: R1/R2 (buck VFB divider, TI requirement),
@@ -137,8 +138,17 @@ W5100S reference schematic, and JLCPCB manufacturing limits. ERC/DRC: clean.
       45° bevel** for the SP1 edge connector.
 - [ ] Hand-solder / non-economic-assembly parts: C65 (THT electrolytic),
       J2 magjack (THT), J1 USB-C, D2 (DFN2111-7, tiny). Plan assembly split.
-- [ ] Add LCSC part numbers to symbol fields for JLC PCBA BOM export; check
-      fiducials for SMT.
+- [x] LCSC part numbers — COMPLETE 2026-07-17: all 112 orderable components
+      have Footprint + Value + MPN + LCSC + Manufacturer (netlist-vs-BOM
+      count check passes; the only netlist/BOM delta is J3, deliberately
+      excluded from BOM since the SP1 edge connector is PCB gold fingers,
+      not a part). 12 V-rail caps verified ≥25 V, divider/REF/RSET resistors
+      verified 1 %. Note: D2 is the **ElecSuper** PUSB3AB6Z(ES) clone
+      (C49383400, Extended), not Nexperia — same DFN-7 1.1×2.1 / 0.15 pF;
+      pin-compatible, but treat as a bring-up suspect if EXI ESD behaviour
+      looks odd. C65 is an SMD electrolytic (Lelon VZH101M1ETR-0607, 25 V) —
+      assembly-friendly, not THT as first assumed.
+- [ ] Check fiducials for SMT assembly.
 
 ## Housekeeping (repo) — done 2026-07-17
 

hardware/re-bba-rb/exi.kicad_sch

@@ -2813,7 +2813,7 @@
 		(unit 1)
 		(body_style 1)
 		(exclude_from_sim no)
-		(in_bom yes)
+		(in_bom no)
 		(on_board yes)
 		(in_pos_files yes)
 		(dnp yes)