docs(render): S3 packet — capture session progress, cathedral-leak retail oracle

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

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

@@ -134,6 +134,22 @@ Lead verifies every finding against the source before an edit (S2 precedent:
   `logs/selfgate-20260903-010022-s2-review-fixes-3` — the per-region diff,
   not the eye, is the verdict ([[feedback-deleted-fallback-carried-population]]).
 
+## 6b. Capture session progress (2026-09-03)
+
+- Recon PASSED against the live 2013 client (`logs/oh-capture/oh-recon.log`):
+  every template offset and breakpoint address matches; globals sane.
+- **Pose `cathedral-leak` (extra, owner-chosen):** standing on the cathedral
+  stairs where the outside structure leaks into the interior — RETAIL SHOWS
+  THE ARTIFACT (2013 and EoR clients both). Transcript:
+  `logs/oh-capture/cathedral-leak.walk.log` (5 frames: DI `f4180108`, DC with
+  `ov=4`, EC/OC stamps, 531 `LC`/`SC` land-cell draws per frame in far-to-near
+  order over landblocks `f3`–`fe` × `00`–`18`), `cathedral-leak.parts.log`
+  (3 frames, 5,933 PD / 965 DM), `cathedral-leak.alphadepth.log` (5 frames,
+  1,407 AM / 2,856 FL / 28 PM / 16 PC). 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`,
+  `terrace-edge`, `foundry-deep`.
+
 ## 7. Open questions for the capture session (ask for exactly these two)
 
 1. `LScape::calc_draw_order` sequence at each of the four poses (far-to-near