docs(render): record the cathedral-arrival retail capture (S3 §6b)

Walk (5 frames), parts (3) and alpha-depth (5) transcripts captured from
the paired 2013 client at the owner's cathedral-arrival pose. The live DI
was f4180108 (stair chamber), not the f4180106 the kit README expected
from FW0's still; recorded as-is. A second PView (009d4530, ov=0) draws
f4180112-14 each frame with no DI of its own -- flagged for chunk 2.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/research/2026-09-01-overhaul/s3-walk-ownership-map.md

@@ -153,7 +153,17 @@ Lead verifies every finding against the source before an edit (S2 precedent:
   it — the same leak acdream shows at the same spot. This pose is S3/S4's
   primary oracle: the target is to reproduce retail's frame at it, leak
   included.
-- Remaining poses per the kit README: `cathedral-arrival`, `holtburg-doorway-still`,
+- **Pose `cathedral-arrival`** (owner "ready" 2026-09-03 06:58): transcript
+  `logs/oh-capture/cathedral-arrival.walk.log` (5 frames, 5,604 lines: main
+  PView `009d4f48` DI `f4180108`, DC `ov=3` n=2 `f4180108 f4180107`; a SECOND
+  PView `009d4530` with `ov=0` draws cells `f4180113/f4180112/f4180114` each
+  frame with no DI of its own — its identity is a chunk-2 audit item; 454
+  `LC` + 619 `SC` per frame, 40 EC / 40 OC total), `cathedral-arrival.parts.log`
+  (3 frames, 7,822 PD / 1,240 DM), `cathedral-arrival.alphadepth.log` (5 frames,
+  1,735 AM / 3,570 FL / 35 PM / 19 PC). NOTE: the kit README expected
+  `DI f4180106` (FW0's arrival still); the live client reported `f4180108`,
+  the stair-chamber cell — the owner's actual standing cell, recorded as-is.
+- Remaining poses per the kit README: `holtburg-doorway-still`,
   `terrace-edge`, `foundry-deep`.
 
 ## 7. Open questions for the capture session (ask for exactly these two)