CARD R1 (RF-U) written 2026-09-26 19:46:49 -0700 (clock-read), BEFORE compiling. Immutable; outcome appended.
Kind: RETAIL WITNESS LAB (diagnostic, zero credit; retail equality is corroboration only). Copies:
  hb_head_retail.c and b/B5_retail.c = HEAD and B5 with each arm's HRESULT test + rasterizer_error removed (bare
  call statement), modelling the Sept-2001 retail body (0x504890: no HRESULT tests, no rasterizer_error) as a
  debug-only per-arm check. Tool: RF-E retail kit copied to scratch/rf/workers/RF-U/retail/rw (rcheck.py, calibrated
  retail config: no /DDEBUG, /Gr, shims), compared with Sept-25-2001 cache.exe and Oct-12 2276P.
Question: does the error() placement (HEAD: inside the device arm with hw = NULL; B5: after the if/else) show in
  retail? Prediction: BOTH forms give the same retail bytes (after constant propagation both reduce to
  'if (!hw) { hw = NULL; error(); return FALSE; } return TRUE;' with the constant-TRUE returns cross-jumped), so the
  retail witness cannot discriminate (p ~0.6); whether either equals Sept exactly: p ~0.5.

OUTCOME R1 (appended 2026-09-26 19:47:18 -0700): HEAD-retail: size 224, SEP short-image (differs: 'success' stays a stack byte [esp+7],
  push ecx frame, ND tail after); OCT no hit. B5-retail: size 208, SEP=MATCH (Sept-25-2001 cache.exe 0x504890) AND
  OCT hit 0x115de0 (Oct-12-2001 2276P). Prediction (retail cannot discriminate) WRONG: the retail witness
  DISCRIMINATES - only B5's return structure reproduces both first-party retail builds.
