wip(assembler): round L32 -- smooth Gradient interface at full amplitude (no rings, not flat)

Band faces now use signed distance to the displaced solid intervals, continuous across bands, so
MC interpolates the interface instead of terracing at density levels. The Gradient amplitude is
restored to width/8 (about 4 m peak-to-peak at 16 m). Ring/terrace audit at LOD0-8 on the FI floor and SW
ceiling passes; negative controls: L30 (rings) and L31 (flat) both fail. Hole/interface audits,
16 passage rows and 24/24 determinism pass. Evaluator 20. Cost vs L31 SW +1.9%, FI +1.5%.

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

Standalone/Research/WorldAssemblerM3/Linux32/RunAuditsL32.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+"""Run the recipe-stamped L31 passage audit matrix and reject mislabeled runs."""
+import json
+import re
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l32"
+OUT.mkdir(parents=True, exist_ok=True)
+BINARIES = {
+    "clang": OUT / "bin/VoxelForgeCoreHeadless-l32-clang-v20",
+    "gcc": OUT / "bin/VoxelForgeCoreHeadless-l32-gcc-v20",
+}
+MARKERS = (
+    "[ResolvedPassageAuditSummary]",
+    "[PassageOpenAirAuditSummary]",
+    "[PassageNaturalnessSummary]",
+    "[PassageNoLongBridgeAudit]",
+    "[PassageRockColumnAuditSummary]",
+)
+rows = []
+failed = False
+
+for recipe in ("surface-world", "floating-islands"):
+    for style in range(4):
+        data = ROOT / f"Saved/Linux/linux25-owner-{recipe}-style{style}.json"
+        for compiler, binary in BINARIES.items():
+            name = f"passage-{recipe}-style{style}-{compiler}"
+            logfile = OUT / f"{name}.log"
+            command = [
+                "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--", 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, stdout=stream, stderr=subprocess.STDOUT,
+                                            timeout=900, check=False)
+            except subprocess.TimeoutExpired:
+                result = None
+            elapsed = time.monotonic() - started
+            text = logfile.read_text(encoding="utf-8", errors="replace")
+            stamps = re.findall(
+                r"^\[WorldAssemblerRecipeAudit\] requested=([^ ]+) actual=([^ ]+).*status=([^ ]+)$",
+                text, re.M)
+            recipe_ok = stamps == [(recipe, recipe, "PASS")]
+            markers_ok = all(re.search(re.escape(marker) + r".*status=PASS", text)
+                             for marker in MARKERS)
+            capsule_ok = bool(re.search(
+                r"^\[ResolvedPassageAudit\].* blocked=0 support_samples=\d+ "
+                r"unsupported=0 grade_failures=0 mouth_content=2/2 mouth_radius=2/2 "
+                r"walkability=PASS$", text, re.M))
+            island_route_ok = (recipe != "floating-islands" or bool(re.search(
+                r"^\[FloatingIslandRouteAudit\].* blocked=0 support_samples=\d+ "
+                r"unsupported=0 grade_failures=0 status=PASS$", text, re.M)))
+            binding_ok = bool(re.search(
+                r"\[ResolvedPassageAuditSummary\].*route_bindings=[1-9][0-9]* "
+                r"route_binding_failures=0 .*status=PASS", text))
+            walk_ok = "[Walkability] PASS" in text
+            if recipe == "floating-islands":
+                control_ok = "[PassageColumnDisconnectedEndControl]" in text and bool(
+                    re.search(r"\[PassageColumnDisconnectedEndControl\].*detected=true", text))
+            else:
+                control_ok = True
+            ok = (result is not None and result.returncode == 0 and recipe_ok
+                  and markers_ok and capsule_ok and island_route_ok and binding_ok
+                  and walk_ok and control_ok)
+            actual_recipe = stamps[0][1] if len(stamps) == 1 else "MISSING"
+            rows.append((recipe, actual_recipe, style, compiler, elapsed,
+                         result.returncode if result else "TIMEOUT", ok))
+            print(f"{name} elapsed={elapsed:.1f}s exit={result.returncode if result else 'TIMEOUT'} "
+                  f"recipe={stamps[0][1] if stamps else 'MISSING'} "
+                  f"capsule={'PASS' if capsule_ok and island_route_ok else 'FAIL'} "
+                  f"column_control={'PASS' if control_ok else 'FAIL'} {'PASS' if ok else 'FAIL'}",
+                  flush=True)
+            if not ok:
+                failed = True
+
+summary = OUT / "passage-audit-matrix.csv"
+summary.write_text(
+    "requested_recipe,actual_recipe,style,compiler,elapsed_seconds,exit_code,status\n" +
+    "".join(f"{requested},{actual},{style},{compiler},{elapsed:.3f},{code},"
+            f"{'PASS' if ok else 'FAIL'}\n"
+            for requested, actual, style, compiler, elapsed, code, ok in rows), encoding="utf-8")
+
+control_log = OUT / "recipe-mismatch-control.log"
+control_owner = OUT / "recipe-mismatch-control-owner.json"
+control_owner_data = json.loads(
+    (ROOT / "Saved/Linux/linux25-owner-surface-world-style0.json").read_text(encoding="utf-8"))
+top_owner_stratum = max(control_owner_data["strates"], key=lambda stratum: stratum["top_chunk_z"])
+top_owner_stratum["asset"]["GeneratorType"] = 6  # ECaveGeneratorType::FloatingIslands
+control_owner.write_text(json.dumps(control_owner_data, separators=(",", ":")), encoding="utf-8")
+control_command = [
+    "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--", str(BINARIES["clang"]),
+    str(control_owner),
+    "--workers=12", "--world-assembler-prototype", "--stream-benchmark",
+    "--stream-pipeline", "--force-generate", "--clip-radius=3",
+    "--max-clip-level=8", "--max-level=-1", "--recipe=surface-world",
+    "--audit-resolved-layout-passages",
+]
+with control_log.open("w", encoding="utf-8") as stream:
+    control = subprocess.run(control_command, stdout=stream, stderr=subprocess.STDOUT,
+                             timeout=900, check=False)
+control_text = control_log.read_text(encoding="utf-8", errors="replace")
+control_ok = (control.returncode == 2 and
+              "[WorldAssemblerRecipeAudit] requested=surface-world actual=floating-islands "
+              "top_generator=FloatingIslands " in control_text and
+              "floating_islands_stratum=present status=FAIL" in control_text)
+print(f"[L32RecipeMismatchControl] requested=surface-world actual=floating-islands "
+      f"exit={control.returncode} detected={'true' if control_ok else 'false'} "
+      f"{'PASS' if control_ok else 'FAIL'}", flush=True)
+
+print(f"[L32PassageMatrix] 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 not control_ok or len(rows) != 16 else 0)