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/Research/WorldAssemblerM3/Linux110/RunL110HashMatrix.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+"""Verify Clang/GCC W1/W8/W12 hashes and pin the v257 shell recipes."""
+from __future__ import annotations
+
+import json
+import re
+import subprocess
+import time
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l110/hashes-v257"
+DATASETS = {
+    "owner4": ROOT / "Standalone/data/owner_world.json",
+    "owner2": ROOT / "Standalone/data/regression/owner_world_2strate_l61.json",
+}
+BINARIES = {
+    "clang": ROOT / "Saved/Linux/l110/bin-clang-v257/VoxelForgeCoreHeadless-l110-clang-v257",
+    "gcc": ROOT / "Saved/Linux/l110/bin-gcc-v257/VoxelForgeCoreHeadless-l110-gcc-v257",
+}
+HASH = re.compile(r"^\[Pipeline(?:FullDetailHash|WholeViewHash|LODHash|ExactQueryHash)\].*$", re.M)
+STAMP = re.compile(r"^\[VoxelForgeSourceStamp\] sha256=(\S+)$", re.M)
+
+
+def run(dataset: str, recipe: str, workers: int, compiler: str) -> dict:
+    OUT.mkdir(parents=True, exist_ok=True)
+    label = f"{dataset}-{recipe}-w{workers}-{compiler}"
+    log = OUT / f"{label}.log"
+    layout = OUT / f"{label}.layout.json"
+    command = [
+        "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+        "timeout", "1740s", str(BINARIES[compiler]), str(DATASETS[dataset]),
+        f"--workers={workers}", "--world-assembler-prototype", "--stream-benchmark",
+        "--stream-pipeline", "--force-generate", "--clip-radius=3",
+        "--max-clip-level=8", "--max-level=8", f"--recipe={recipe}",
+        "--stream-hash", f"--resolved-layout-output={layout}",
+    ]
+    started = time.monotonic()
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run(command, cwd=ROOT, stdout=stream,
+                                stderr=subprocess.STDOUT, check=False, timeout=1740)
+    output = log.read_text(encoding="utf-8", errors="replace")
+    hashes = HASH.findall(output)
+    if result.returncode or len(hashes) != 12:
+        raise SystemExit(f"hash run failed or incomplete: {label}; exit={result.returncode} "
+                         f"hashes={len(hashes)} log={log}")
+    stamp = STAMP.search(output)
+    row = {"dataset": dataset, "recipe": recipe, "workers": workers,
+           "compiler": compiler, "exit_code": result.returncode, "hashes": hashes,
+           "source_stamp": stamp.group(1) if stamp else None,
+           "elapsed_s": round(time.monotonic() - started, 3),
+           "log": str(log.relative_to(ROOT))}
+    print("[L110HashRun] " + json.dumps(row, sort_keys=True), flush=True)
+    return row
+
+
+def main() -> int:
+    if any(not path.is_file() for path in (*DATASETS.values(), *BINARIES.values())):
+        raise SystemExit("missing L110 hash input")
+    rows = []
+    recipes = {"owner4": ("surface-world",),
+               "owner2": ("surface-world", "floating-islands")}
+    for dataset, dataset_recipes in recipes.items():
+        for recipe in dataset_recipes:
+            for workers in (1, 8, 12):
+                for compiler in ("clang", "gcc"):
+                    rows.append(run(dataset, recipe, workers, compiler))
+                    (OUT / "runs-partial.json").write_text(
+                        json.dumps(rows, indent=2) + "\n", encoding="utf-8")
+    groups = {}
+    for dataset, dataset_recipes in recipes.items():
+        for recipe in dataset_recipes:
+            key = f"{dataset}/{recipe}"
+            group = [row for row in rows if row["dataset"] == dataset
+                     and row["recipe"] == recipe]
+            reference = group[0]["hashes"]
+            matches = all(row["hashes"] == reference for row in group)
+            groups[key] = {"all_worker_compiler_hashes_match": matches,
+                           "source_stamps": sorted({row["source_stamp"] for row in group}),
+                           "runs": [{"workers": row["workers"], "compiler": row["compiler"],
+                                     "log": row["log"]} for row in group]}
+            if not matches:
+                raise SystemExit(f"determinism mismatch: {key}")
+            if dataset == "owner2":
+                canonical = next(row for row in group if row["workers"] == 12
+                                 and row["compiler"] == "clang")
+                style = 1 if recipe == "surface-world" else 2
+                baseline = (ROOT / "Standalone/Tools/verify/baselines/owner-hash/canonical"
+                            / f"owner-hash-{recipe}-style{style}-v257.baseline")
+                baseline.write_text("\n".join(canonical["hashes"]) + "\n",
+                                    encoding="utf-8")
+    summary = {"runs": rows, "groups": groups,
+               "owner4_all_four_strata": "owner4/surface-world",
+               "owner2_canonical_pins": ["owner2/surface-world",
+                                          "owner2/floating-islands"]}
+    (OUT / "summary.json").write_text(json.dumps(summary, indent=2) + "\n",
+                                      encoding="utf-8")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())