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/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)