wip(assembler): round L35 -- smooth passage walls without regular ribs (evaluator v21)

The shared passage carve took the minimum of piecewise-linear capsules (scallops at joins) and added
wall relief on regular 8 m / 4 m octaves, which read as evenly spaced ribs. Interior sweep joins are
now Catmull-Rom smoothed and the relief uses irregular rotated 43/29/19 m scales; the natural wobble
remains. New axial ripple audit (0.125 m radius samples, 0.5-8 m periods): beaded control and L34
geometry fail, all 24 passage rows pass. FI mouth tread apron tapered. 30/30 determinism, 16/16
invariants, ring audits LOD0-8 pass; cost within noise.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CSFYgsdW8ejZSyiMf4qRSX

ARCHITECTURE.md

@@ -2110,6 +2110,34 @@ when SurfaceWorld is the upper strate. No evaluator or recipe version changed.
 [`Standalone/Research/WorldAssemblerM3/Linux33/REPORT.md`](Standalone/Research/WorldAssemblerM3/Linux33/REPORT.md)
 records the four-style audits, captures, determinism, owner hashes, costs and retries.
 
+### 8.48 Irregular passage-wall relief and grounded tread shoulders — World Assembler M3 L35
+
+L34's owner-SW profile had a 7.438 m radius repeat with 0.0361 m (3.61 cm) amplitude; an independent
+mesh-normal scan also found a 4.750 m period at 0.02682 (1.537°). The geometry came from piecewise
+capsule joins, while broad value-noise bands added a second regular pattern. The shared carve now
+uses Catmull–Rom centerline interpolation on eligible interior segments, excluding short spans and
+terminal controls. Passage walls use deterministic, rotated 43/29/19 m relief with reduced terrain
+band contribution; other `VF_FieldSurfaceRelief` users, including grounded bridge columns, are
+unchanged. The shared evaluator is version 21.
+
+The residual radius scan on owner-SW style 0 measures a 7.062 m period at 0.0109 m (1.09 cm),
+with 0.0044 m (0.44 cm) coherent amplitude. The independent L35 mesh-normal scan passes at 8 m
+and 0.02496 axial amplitude, below its 0.0255 threshold. The ripple audit samples both side-wall
+radii every 0.125 m in 32 m windows, scans 0.5–8 m periods, and rejects amplitudes of 0.035 m or
+more. Its synthetic control uses 2 m radius spheres spaced every 1.5 m; it measures 0.0599 m and
+must fail.
+
+At the FI mouth, the flat apron is the shared passage support tread, not `LandingExtensionQ`, a tile
+edge or a separate support layer. The tread is required by capsule and support probes. L35 gives its
+outer entry shoulder a shallow taper and seeded grain while preserving the supported walk core and
+lower-mouth overlap width. The shallow quarter-weight support-height/radius spline keeps the tread
+continuous without moving its XY footprint.
+
+Cascade routes also replace identical full-depth cosine lobes with a seeded shallow profile on each
+turn. Passage, capsule, support, open-air, bridge, binding, strict layout, capture, determinism, ring,
+and cost evidence are recorded in
+[`Standalone/Research/WorldAssemblerM3/Linux35/REPORT.md`](Standalone/Research/WorldAssemblerM3/Linux35/REPORT.md).
+
 ## 9. Multiplayer model (listen-server first, dedicated-friendly)
 
 > **Status: transport is DESIGN ONLY — nothing is networked in-tree yet** (no `Replicated`/`HasAuthority`/RPCs; a