skip: sound whole-tile proofs for legacy FI/TN/VS fields (L74); FI -30%, TN -22%

The compiled-analytic stratum interval now certifies a legacy tile uniform only when it stays
beyond the detail envelope (and smooth-min slack for solid) with no intersecting primitive,
edit, native field, composer candidate, passage or active transition; everything else fails
closed. The stream layer uses the proof for whole-tile skips; legacy sub-tile skips stay off
(two block proofs failed the falsifier in TN).

Falsifier: full-grid reference vs skip-enabled run, identical mesh/payload/topology hashes on
every tile of all four owner views, Clang and GCC, W1/W8/W12; 20-camera sweep per strate,
0 violations; a too-tight control changed 3/184/233/238 tiles and was caught.
Whole view (8 workers): SW 2.61->2.48, FI 7.18->5.05, TN 5.97->4.63, VS 2.70->2.40 s.

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

Standalone/Research/WorldAssemblerM3/Linux74/RunTimingPairsL74.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+"""Run three interleaved clean full-view pairs on L73 and L74 headless builds."""
+from __future__ import annotations
+
+import json
+import re
+import statistics
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l74/logs/timing"
+DATA = ROOT / "Standalone/data/owner_world.json"
+BINARIES = {
+    "before": ROOT / "Saved/Linux/l73/bin/VoxelForgeCoreHeadless-l73-clang",
+    "after": ROOT / "Saved/Linux/l74/bin/VoxelForgeCoreHeadless-l74-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),
+}
+ORDERS = (("before", "after"), ("after", "before"), ("before", "after"))
+PIPELINE = re.compile(r"\[StreamPipeline\] (.*)")
+PAIR = re.compile(r"([a-zA-Z0-9_]+)=([^ ]+)")
+
+
+def run(strate: int, pair: int, mode: str) -> dict:
+    label = f"strate{strate}-pair{pair}-{mode}"
+    log = OUT / f"{label}.log"
+    camera = ",".join(f"{value:.12f}" for value in CAMERAS[strate]) + ",0,0"
+    command = [
+        "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--", "timeout",
+        "1740s", str(BINARIES[mode]), str(DATA), "--world-assembler-prototype",
+        "--stream-benchmark", "--stream-pipeline", "--force-generate", "--workers=8",
+        "--clip-radius=3", "--max-clip-level=8", "--max-level=8", f"--camera={camera}",
+    ]
+    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")
+    match = PIPELINE.search(content)
+    if result.returncode != 0 or match is None:
+        raise SystemExit(f"timing run failed or missing StreamPipeline summary; see {log}")
+    pipeline = dict(PAIR.findall(match.group(1)))
+    row = {
+        "strate": strate, "pair": pair, "mode": mode, "exit_code": result.returncode,
+        "process_wall_s": round(time.monotonic() - started, 3),
+        "whole_view_ready_s": float(pipeline["whole_view_ready"].removesuffix("s")),
+        "stream_wall_s": float(pipeline["stream_wall"].removesuffix("s")),
+        "whole_tiles": int(pipeline["whole_tiles"].split("/")[0]),
+        "source_stamp": re.search(r"\[VoxelForgeBuild\] source_stamp=(\S+)", content),
+        "log": str(log.relative_to(ROOT)),
+    }
+    row["source_stamp"] = row["source_stamp"].group(1) if row["source_stamp"] else None
+    print("[L74TimingPairRun] " + json.dumps(row, sort_keys=True), flush=True)
+    return row
+
+
+def main() -> int:
+    OUT.mkdir(parents=True, exist_ok=True)
+    missing = [str(path) for path in [DATA, *BINARIES.values()] if not path.is_file()]
+    if missing:
+        raise SystemExit("missing input: " + ", ".join(missing))
+    rows = []
+    for strate in range(4):
+        for pair, order in enumerate(ORDERS, 1):
+            for mode in order:
+                rows.append(run(strate, pair, mode))
+    summary = []
+    for strate in range(4):
+        group = [row for row in rows if row["strate"] == strate]
+        before = [row["whole_view_ready_s"] for row in group if row["mode"] == "before"]
+        after = [row["whole_view_ready_s"] for row in group if row["mode"] == "after"]
+        summary.append({"strate": strate, "pairs": len(before),
+                        "before_s": [round(value, 3) for value in before],
+                        "after_s": [round(value, 3) for value in after],
+                        "before_median_s": round(statistics.median(before), 3),
+                        "after_median_s": round(statistics.median(after), 3),
+                        "change_pct": round(100.0 * (statistics.median(after)
+                            / statistics.median(before) - 1.0), 2)})
+    result = {"runs": rows, "summary": summary}
+    (OUT / "summary.json").write_text(json.dumps(result, indent=2) + "\n",
+                                      encoding="utf-8")
+    for row in summary:
+        print("[L74TimingPairSummary] " + json.dumps(row, sort_keys=True), flush=True)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())