core: per-tile passage route IDs and empty-feature early outs (L136, output = v236)

Passage visits -78..-89% near-ready; composer worker time back to baseline on Tunnel Network; v239 is 2-4% faster
than v236 in 7/8 cells but still +4.3..+13.3% near-ready vs assembler/world. Surface World composer time equals
baseline yet near-ready is +4-6%: unexplained. 16/16 seeds, fast tier, Clang/GCC green.

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

Standalone/Research/WorldAssemblerM3/Linux136/RunL136Determinism.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+"""Check exact-stamp Clang/GCC cave-path hashes at 1, 8, and 12 workers."""
+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/l136/determinism"
+DATA = ROOT / "Standalone/data/regression/owner_world_2strate_l61.json"
+BINARIES = {
+    "clang": ROOT / "Saved/Linux/l136/fast/bin/VoxelForgeCoreHeadless-fast-clang",
+    "gcc": ROOT / "Saved/Linux/l136/fast/bin/VoxelForgeCoreHeadless-fast-gcc",
+}
+STAMP = "ebe6b32a7cd96c5aa69c6dc64ae6b9c6ff4bc18bc484efc5148611c48723c28f"
+CAMERA = "-4.688214,38.662384,-505.781342,-28.446,0"
+HASH_RE = re.compile(
+    r"^\[Pipeline(?:FullDetailHash|WholeViewHash|MaterialHash|LODHash|ExactQueryHash)\].*$",
+    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 L136 determinism binary or owner fixture")
+    OUT.mkdir(parents=True, exist_ok=True)
+    rows = []
+    baseline: tuple[str, ...] | None = None
+    for compiler, binary in BINARIES.items():
+        for workers in (1, 8, 12):
+            label = f"determinism-{compiler}-w{workers}"
+            log = OUT / f"{label}.log"
+            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=0",
+                "--max-level=0", f"--camera={CAMERA}", "--stream-hash-tiles",
+                "--force-generate", "--recipe=surface-world", "--render-distance-chunks=0",
+                "--landmark-chamber-demo", "--ore-veins-demo"]
+            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")
+            found_stamp = STAMP_RE.search(content)
+            hashes = tuple(HASH_RE.findall(content))
+            passed = (result.returncode == 0 and found_stamp is not None
+                and found_stamp.group(1) == STAMP and len(hashes) >= 4)
+            if baseline is None and passed:
+                baseline = hashes
+            elif baseline is not None:
+                passed &= hashes == baseline
+            row = {"compiler": compiler, "workers": workers,
+                "exit": result.returncode, "stamp": found_stamp.group(1)
+                    if found_stamp else None,
+                "hash_lines": len(hashes), "hashes_match_first": hashes == baseline,
+                "passed": bool(passed), "elapsed_s": round(time.monotonic() - started, 3),
+                "log": str(log.relative_to(ROOT))}
+            rows.append(row)
+            print("[L136DeterminismRun] " + json.dumps(row, sort_keys=True), flush=True)
+            if not passed:
+                (OUT / "summary.json").write_text(json.dumps(
+                    {"status": "FAIL", "stamp": STAMP, "runs": rows}, indent=2) + "\n")
+                raise SystemExit(f"determinism mismatch; see {log}")
+    (OUT / "summary.json").write_text(json.dumps(
+        {"status": "PASS", "stamp": STAMP, "runs": rows}, indent=2) + "\n")
+    print(f"[L136DeterminismSummary] runs={len(rows)} stamp={STAMP} status=PASS")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())