passages: smoothed open-air shell joins (L110, v257) - partial, not merged

Bands = end profiles of per-control-span shell capsules (~9.35 m pitch = span spacing).
Shell now smooth-unions adjacent spans over 6 m and reuses the interior chord distance; a 0.60 m
clearance fades in 5-20 m from each mouth. Close-ups: bands reduced but still visible on part of
the exposed shell. Cost vs L109: near-ready +8..+12% (FI 0.88 -> 1.00, TN 0.92 -> 1.01 s @W12).
Audits, Clang/GCC determinism, fast tier and Linux UE build pass. Kept on its own branch.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Tools/verify/verify.py

@@ -122,11 +122,11 @@ RECIPE_RE = re.compile(
 
 def owner_hash_baseline(recipe: str, style: int) -> tuple[Path, str]:
     if recipe == "surface-world" and style == 1:
-        return (BASELINES / "owner-hash/canonical/owner-hash-surface-world-style1-v217.baseline",
-                "L109-v217-flat-floor-hollow-shell")
+        return (BASELINES / "owner-hash/canonical/owner-hash-surface-world-style1-v257.baseline",
+                "L110-v257-smoothed-openair-shell")
     if recipe == "floating-islands" and style == 2:
-        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-v217.baseline",
-                "L109-v217-flat-floor-hollow-shell")
+        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-v257.baseline",
+                "L110-v257-smoothed-openair-shell")
     raise VerificationFailure(f"no pinned owner hash baseline for {recipe} style {style}")
 
 
@@ -696,7 +696,7 @@ def run_hash_pairs(runner: VerificationRunner,
             diagnostic = {"name": "owner-hash-surface-world-matches-L52-diagnostic",
                 "status": "DIAGNOSTIC",
                 "detail": f"matches={hashes[12] == l52_hashes} L52 rows={len(l52_hashes)}; "
-                    "the v217 flat-floor hollow-shell geometry has its own pinned baseline"}
+                    "the v257 smoothed open-air shell has its own pinned baseline"}
             runner.steps.append(diagnostic)
             print(f"[{runner.tier}] {diagnostic['name']} {diagnostic['detail']}", flush=True)
         baseline = BASELINES / "owner-hash/l46" / f"owner-hash-{recipe}-style{style}-w12.baseline"