research: one continuous tube through the mouth (L149, 0/16; kept as patch)

Mouth edges matched passage position, radius, tangent (dot 0.99999) and floor slope, but the cubic departure edge
still curls ~1 m back alongside the passage within 5 m; shell floor violations remain; composed sweeps 0/16.
Sixth mouth-join round (L144-L149): stop and take the design question to the owner.

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

Standalone/Research/WorldAssemblerM3/Linux149/RunL149Determinism.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+"""Compare L149 hashes and layout identity at Clang/GCC W1, W8, and W12."""
+from __future__ import annotations
+
+import json
+import re
+import subprocess
+import time
+from pathlib import Path
+
+from MouthAudit import audit_layout
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l149/determinism"
+DATA = ROOT / "Standalone/data/owner_world.json"
+BINARIES = {
+    "clang": ROOT / "Standalone/bin/linux/VoxelForgeCoreHeadless-l149-clang",
+    "gcc": ROOT / "Standalone/bin/linux/VoxelForgeCoreHeadless-l149-gcc",
+}
+STAMP = "19dbe26ab76a629baadc54bb0ab93eaa22d6f878e6946df2b71509c12c9524e4"
+CAMERA = "-20.062500,-5.068359,-900.353516,0,0"
+HASH_RE = re.compile(
+    r"^\[Pipeline(?:FullDetailHash|WholeViewHash|LODHash|ExactQueryHash)\].*$",
+    re.M)
+STAMP_RE = re.compile(r"^\[VoxelForgeSourceStamp\] sha256=([0-9a-f]+)$", re.M)
+
+
+def main() -> int:
+    if any(not path.is_file() for path in (DATA, *BINARIES.values())):
+        raise SystemExit("missing L149 Clang/GCC binary or composed owner fixture")
+    OUT.mkdir(parents=True, exist_ok=True)
+    rows = []
+    partial = OUT / "runs-partial.json"
+    for compiler, binary in BINARIES.items():
+        for workers in (1, 8, 12):
+            name = f"determinism-{compiler}-w{workers}"
+            log, layout = OUT / f"{name}.log", OUT / f"{name}.json"
+            command = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+                "timeout", "1740s", str(binary), str(DATA), "--world-assembler-prototype",
+                "--stream-benchmark", "--stream-pipeline", f"--workers={workers}",
+                "--clip-radius=3", "--max-clip-level=8", "--max-level=0",
+                f"--camera={CAMERA}", "--stream-hash", "--force-generate", "--seed=2",
+                "--recipe=surface-world", "--render-distance-chunks=0",
+                "--density-dispatch-report", f"--resolved-layout-output={layout}"]
+            started = time.monotonic()
+            with log.open("w", encoding="utf-8") as output:
+                proc = subprocess.run(command, cwd=ROOT, stdout=output,
+                                      stderr=subprocess.STDOUT, check=False, timeout=1740)
+            content = log.read_text(encoding="utf-8", errors="replace")
+            stamp_match = STAMP_RE.search(content)
+            stamp = stamp_match.group(1) if stamp_match else None
+            hashes = tuple(HASH_RE.findall(content))
+            identity = (json.loads(layout.read_text(encoding="utf-8")).get("stable_identity")
+                        if layout.is_file() else None)
+            mouth_audit = audit_layout(layout) if layout.is_file() else None
+            row = {"compiler": compiler, "workers": workers, "exit": proc.returncode,
+                   "stamp": stamp, "source_stamp_matches": stamp == STAMP,
+                   "hash_lines": len(hashes), "hashes": hashes,
+                   "layout_identity": identity,
+                   "mouth_audit": mouth_audit,
+                   "elapsed_s": round(time.monotonic() - started, 3),
+                   "log": str(log.relative_to(ROOT)), "layout": str(layout.relative_to(ROOT))}
+            rows.append(row)
+            partial.write_text(json.dumps(rows, indent=2) + "\n", encoding="utf-8")
+            print("[L149DeterminismRun] " + json.dumps(row, sort_keys=True), flush=True)
+    valid = [row for row in rows if row["source_stamp_matches"]
+             and row["hash_lines"] == 12 and row["layout_identity"]]
+    reference_hashes = valid[0]["hashes"] if valid else []
+    reference_identity = valid[0]["layout_identity"] if valid else None
+    deterministic = len(valid) == 6 and all(
+        row["hashes"] == reference_hashes and row["layout_identity"] == reference_identity
+        for row in valid)
+    mouth_geometry = all(row["mouth_audit"] and row["mouth_audit"]["continuity"]
+                         and row["mouth_audit"]["negative_controls_pass"]
+                         for row in rows)
+    no_backtrack = all(row["mouth_audit"] and row["mouth_audit"]["no_backtrack_12m"]
+                       for row in rows)
+    summary = {"status": "PASS" if deterministic else "FAIL",
+               "deterministic": deterministic, "mouth_geometry_pass": mouth_geometry,
+               "no_backtrack_12m": no_backtrack,
+               "source_stamp": STAMP, "layout_identity": reference_identity, "runs": rows}
+    (OUT / "summary.json").write_text(json.dumps(summary, indent=2) + "\n",
+                                      encoding="utf-8")
+    print(f"[L149DeterminismSummary] runs={len(rows)} deterministic="
+          f"{'PASS' if deterministic else 'FAIL'} mouth_geometry="
+          f"{'PASS' if mouth_geometry else 'FAIL'} no_backtrack_12m="
+          f"{'PASS' if no_backtrack else 'FAIL'} status={summary['status']}", flush=True)
+    return 0 if summary["status"] == "PASS" else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())