wip(assembler): round L37 -- FI mouth carve-fade fix, no raised bridge (style 0); research R1

The passage mouth fade multiplied the signed carve distance by zero, which turned native rock into an
open surface (the reason earlier rounds stamped walk pads at mouths); it now blends between the
uncarved field and the full signed carve. The FI style-0 route followed a lifted grade envelope over
the crater (the "bridge"); it now runs on the rim and follows the native surface. New built-shape and
crease audits with thresholds frozen before the fix (L36 and box controls fail). 24/24 passage rows,
30/30 determinism, 16/16 invariants, 18/18 interface/ring. Unreal: one recipe setter (uncompiled).
Research R1 (read-only, web): ranked proposals for natural walkable mouths, floor-limited carve first.

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

Standalone/Research/WorldAssemblerM3/Linux37/RunPassageAuditsL37.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+"""Run recipe-stamped passage/profile audits for both compilers and both owner recipes."""
+import re
+import os
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l37"
+BINARIES = {
+    "clang": OUT / "bin/VoxelForgeCoreHeadless-l37-final-clang",
+    "gcc": OUT / "bin/VoxelForgeCoreHeadless-l37-final-gcc",
+}
+RUNS = []
+for recipe, filename in (
+    ("floating-islands", "floating-islands"),
+    ("surface-world", "surface-world"),
+):
+    for style in range(4):
+        RUNS.append((f"owner-{filename}-style{style}",
+            ROOT / f"Saved/Linux/linux25-owner-{filename}-style{style}.json", recipe))
+for style in range(4):
+    RUNS.append((f"upper-sw-fixture-style{style}",
+        OUT.parent / "l33/fixtures" / f"sw-upper-tunnel-network-style{style}.json",
+        "floating-islands"))
+
+RECIPE = re.compile(r"^\[WorldAssemblerRecipeAudit\] requested=([^ ]+) actual=([^ ]+).*status=PASS$", re.M)
+PASSAGE = re.compile(r"^\[ResolvedPassageAudit\].*walkability=PASS$", re.M)
+MOUTH = re.compile(r"^\[PassageMouthProfileAudit\].*status=PASS$", re.M)
+ROUTE = re.compile(r"^\[ResolvedStrateRouteAudit\].*mouth_binding=PASS status=PASS$", re.M)
+CHECKS = (
+    r"^\[ResolvedLayoutStrict\] accepted=true issues=0 error=$",
+    r"^\[ResolvedLayoutValidatorControls\].*status=PASS$",
+    r"^\[PassageMouthProfileNegativeControl\].*source=L23_terraced_geometry.*detected=true$",
+    r"^\[PassageMouthProfileSummary\].*l23_terrace_negative_control=DETECTED status=PASS$",
+    r"^\[PassageNaturalnessSummary\].*l23_negative_control=DETECTED.*status=PASS$",
+    r"^\[PassageRippleAuditSummary\].*synthetic_spheres_negative_control=DETECTED max_amplitude_m=0\.035 floor_beaded_negative_control=DETECTED max_floor_amplitude_m=0\.015 status=PASS$",
+    r"^\[PassageOpenAirAuditSummary\].*violations=0.*l24_negative_control=DETECTED status=PASS$",
+    r"^\[PassageNoLongBridgeAudit\].*status=PASS$",
+    r"^\[PassageRockColumnAuditSummary\].*status=PASS$",
+    r"^\[ResolvedPassageAuditSummary\].*route_binding_failures=0 .*status=PASS$",
+    r"^\[Walkability\] PASS",
+    r"^\[FloorProfileBlend\].*negative_controls=step_detected/slope_detected status=PASS$",
+)
+
+rows = []
+failed = False
+for compiler, binary in BINARIES.items():
+    for name, data, recipe in RUNS:
+        logfile = OUT / f"passage-audit-{name}-{compiler}.log"
+        command = [
+            "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+            "timeout", "1800s", str(binary), str(data), "--workers=12",
+            "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+            "--force-generate", "--clip-radius=3", "--max-clip-level=8", "--max-level=-1",
+            f"--recipe={recipe}", "--audit-resolved-layout-passages",
+        ]
+        started = time.monotonic()
+        try:
+            with logfile.open("w", encoding="utf-8") as stream:
+                result = subprocess.run(command, cwd=ROOT, stdout=stream,
+                    stderr=subprocess.STDOUT, timeout=1800, check=False)
+        except subprocess.TimeoutExpired:
+            result = None
+        elapsed = time.monotonic() - started
+        output = logfile.read_text(encoding="utf-8", errors="replace")
+        stamp_ok = RECIPE.findall(output) == [(recipe, recipe)]
+        passages = len(PASSAGE.findall(output))
+        mouths = len(MOUTH.findall(output))
+        routes = len(ROUTE.findall(output))
+        checks_ok = all(re.search(pattern, output, re.M) for pattern in CHECKS)
+        ok = (result is not None and result.returncode == 0 and stamp_ok
+              and passages >= 1 and mouths == passages and routes >= 1 and checks_ok)
+        code = result.returncode if result is not None else "TIMEOUT"
+        rows.append((name, recipe, compiler, elapsed, code, passages, mouths, routes, ok))
+        failed |= not ok
+        print(f"[L37PassageAuditRun] case={name} compiler={compiler} recipe={recipe} "
+              f"elapsed={elapsed:.1f}s exit={code} passages={passages} "
+              f"profiles={mouths} routes={routes} {'PASS' if ok else 'FAIL'} "
+              f"log={logfile}", flush=True)
+
+summary = OUT / "passage-audits.csv"
+summary.write_text(
+    "case,recipe,compiler,elapsed_seconds,exit_code,passages,mouth_profiles,routes,status\n" +
+    "".join(f"{name},{recipe},{compiler},{elapsed:.3f},{code},{passages},{mouths},{routes},"
+        f"{'PASS' if ok else 'FAIL'}\n"
+        for name, recipe, compiler, elapsed, code, passages, mouths, routes, ok in rows),
+    encoding="utf-8")
+print(f"[L37PassageAuditSummary] runs={len(rows)} pass={sum(row[-1] for row in rows)} "
+      f"fail={sum(not row[-1] for row in rows)} summary={summary}", flush=True)
+raise SystemExit(1 if failed or len(rows) != 24 else 0)