docs+cleanup: CURRENT-STATE.md and dead L86/L88 ablation switches removed (L131)

One current-state page (shipping behaviour, references with sources, gaps, verification, closed lines), linked from
CLAUDE.md. Removes the L86/L88 passage/boundary ablation switches and the unused legacy route-grade audit; inventory
of every kept switch in the report. Output identical: 24/24 + 18/18 hashes, fast tier, walk/seam audits, UE host
build; timing unchanged (-0.2%, CI spans 0). No Source/ changes.

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

Standalone/Research/WorldAssemblerM3/Linux131/RunL131Timing.py

@@ -0,0 +1,115 @@
+#!/usr/bin/env python3
+"""Five interleaved L80 readiness measurements per stratum and worker count."""
+from __future__ import annotations
+
+import json
+import os
+import re
+import statistics
+import subprocess
+import time
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l131/timing"
+DATA = ROOT / "Standalone/data/owner_world.json"
+BINARIES = {
+    "base": ROOT / "Saved/Linux/l130/bin/VoxelForgeCoreHeadless-l130-clang",
+    "l131": ROOT / "Saved/Linux/l131/bin/VoxelForgeCoreHeadless-l131-clang",
+}
+CAMERAS = {
+    0: (8.0, 16.0, -372.2626953125),
+    1: (25.8369140625, 3.19921875, -737.0),
+    2: (19.166015625, -14.2001953125, -753.3740234375),
+    3: (-20.0625, -5.068359375, -900.353515625),
+}
+PIPELINE_RE = re.compile(r"^\[StreamPipeline\] (.*)$", re.M)
+FIELDS_RE = re.compile(r"([a-zA-Z0-9_]+)=([^ ]+)")
+NEAR_RE = re.compile(r"^\[WorldAssemblerNearLODReady\] lods=0-2 tiles=(\d+)/(\d+) cold_ready_s=([0-9.]+)$", re.M)
+
+
+def run(strate: int, workers: int, version: str, phase: str, replicate: int) -> dict:
+    camera = ",".join(f"{value:.12f}" for value in CAMERAS[strate]) + ",0,0"
+    label = f"s{strate}-w{workers}-{version}-{phase}{replicate}-l131-v227"
+    log = OUT / f"{label}.log"
+    command = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+        "timeout", "1740s", str(BINARIES[version]), str(DATA),
+        "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        f"--workers={workers}", "--clip-radius=3", "--max-clip-level=8",
+        "--max-level=8", f"--camera={camera}", "--profile-lod-work",
+        "--stream-scheduler-policy=3"]
+    started = time.monotonic()
+    with log.open("w", encoding="utf-8") as output:
+        result = subprocess.run(command, cwd=ROOT, stdout=output,
+            stderr=subprocess.STDOUT, check=False, timeout=1740)
+    content = log.read_text(encoding="utf-8", errors="replace")
+    pipeline, near = PIPELINE_RE.search(content), NEAR_RE.search(content)
+    if result.returncode or pipeline is None or near is None:
+        raise RuntimeError(f"timing run failed: {log}; exit={result.returncode}")
+    fields = dict(FIELDS_RE.findall(pipeline.group(1)))
+    row = {"strate": strate, "workers": workers, "version": version,
+        "phase": phase, "replicate": replicate,
+        "lod02_ready_s": float(near.group(3)),
+        "whole_view_ready_s": float(fields["whole_view_ready"].removesuffix("s")),
+        "wall_s": round(time.monotonic() - started, 3),
+        "log": str(log.relative_to(ROOT))}
+    print("[L131TimingRun] " + json.dumps(row, sort_keys=True), flush=True)
+    return row
+
+
+def quiet_machine() -> tuple[float, float]:
+    load_1m = os.getloadavg()[0]
+    def totals() -> tuple[int, int]:
+        fields = Path("/proc/stat").read_text().splitlines()[0].split()
+        values = [int(value) for value in fields[1:]]
+        return sum(values), values[3] + (values[4] if len(values) > 4 else 0)
+    before = totals()
+    time.sleep(2.0)
+    after = totals()
+    idle = 100.0 * (after[1] - before[1]) / max(1, after[0] - before[0])
+    return load_1m, idle
+
+
+def main() -> int:
+    if any(not path.is_file() for path in (DATA, *BINARIES.values())):
+        raise SystemExit("missing timing input")
+    OUT.mkdir(parents=True, exist_ok=True)
+    load_1m, idle = quiet_machine()
+    (OUT / "machine-load-before.txt").write_text(
+        f"1-minute load: {load_1m:.2f}\n2-second CPU idle: {idle:.1f}%\n")
+    print(f"[L131TimingGate] load_1m={load_1m:.2f} cpu_idle_2s={idle:.1f}%", flush=True)
+    if load_1m >= 0.9 or idle < 97.0:
+        raise SystemExit("timing refused: machine is above the L80 quiet-load gate")
+
+    rows = []
+    for strate in range(4):
+        for workers in (8, 12):
+            for version in BINARIES:
+                rows.append(run(strate, workers, version, "warmup", 0))
+            for replicate in range(1, 6):
+                order = tuple(BINARIES) if replicate % 2 else tuple(reversed(BINARIES))
+                for version in order:
+                    rows.append(run(strate, workers, version, "measured", replicate))
+                    (OUT / "runs-partial.json").write_text(json.dumps(rows, indent=2) + "\n")
+
+    measured = [row for row in rows if row["phase"] == "measured"]
+    summary = []
+    for strate in range(4):
+        for workers in (8, 12):
+            old = [row for row in measured if row["strate"] == strate and row["workers"] == workers and row["version"] == "base"]
+            new = [row for row in measured if row["strate"] == strate and row["workers"] == workers and row["version"] == "l131"]
+            item = {"strate": strate, "workers": workers, "replicates_per_version": 5}
+            for key in ("lod02_ready_s", "whole_view_ready_s"):
+                old_med, new_med = statistics.median(row[key] for row in old), statistics.median(row[key] for row in new)
+                item[f"base_{key}_median"] = old_med
+                item[f"l131_{key}_median"] = new_med
+                item[f"delta_pct_{key}"] = round(100.0 * (new_med / old_med - 1.0), 2)
+                item[f"base_{key}_values"] = [row[key] for row in old]
+                item[f"l131_{key}_values"] = [row[key] for row in new]
+            summary.append(item)
+    (OUT / "summary.json").write_text(json.dumps({"runs": rows, "summary": summary}, indent=2) + "\n")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())