wip(assembler): round L33 -- SurfaceWorld can be an upper strate; FloorProfileBlend measures seams

Route planning for an upper SurfaceWorld failed on long candidate chords over steep relief; chords
are now capped to the arrival/departure radii on an 8 m centre grid with an origin-proximity cost
(21.5 m walk, about 4 deg). The departure passage starts at the SW ground and tunnels down through rock.
FI -> SW -> TN fixture: all 4 styles pass every passage audit on both compilers. FloorProfileBlend
now checks endpoint height/tangent seams (step and tangent-step negative controls detected). Owner
world hashes unchanged; 30/30 determinism; cost within noise.

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

Standalone/Research/WorldAssemblerM3/Linux33/RunCostL33.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Run five interleaved W12 whole-view pairs against the L32 binary."""
+import re
+import statistics
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l33"
+OUT.mkdir(parents=True, exist_ok=True)
+BINARIES = {
+    "l32": ROOT / "Saved/Linux/l32/bin/VoxelForgeCoreHeadless-l32-clang-v20",
+    "l33": OUT / "bin/VoxelForgeCoreHeadless-clang-l33-final",
+}
+ORDERS = (("l32", "l33"), ("l33", "l32"), ("l32", "l33"),
+          ("l33", "l32"), ("l32", "l33"))
+READY = re.compile(r"\bwhole_view_ready=([0-9.]+)s")
+rows = []
+failed = False
+
+
+for recipe in ("surface-world", "floating-islands"):
+    for pair, order in enumerate(ORDERS, 1):
+        for build in order:
+            name = f"cost-{recipe}-pair{pair}-{build}"
+            logfile = OUT / f"{name}.log"
+            command = [
+                "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+                str(BINARIES[build]), str(ROOT / "Standalone/data/owner_world.json"),
+                "--workers=12", "--world-assembler-prototype", "--stream-benchmark",
+                "--stream-pipeline", "--force-generate", "--clip-radius=3",
+                "--max-clip-level=8", "--max-level=-1", f"--recipe={recipe}",
+            ]
+            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")
+            matches = READY.findall(text)
+            stamps = re.findall(
+                r"^\[WorldAssemblerRecipeAudit\] requested=([^ ]+) actual=([^ ]+).*status=([^ ]+)$",
+                text, re.M)
+            stamp_ok = stamps == [(recipe, recipe, "PASS")]
+            valid = (result is not None and result.returncode == 0 and len(matches) == 1
+                     and "hash=off" in text and "cache_hits=0" in text and stamp_ok)
+            ready = float(matches[0]) if len(matches) == 1 else float("nan")
+            rows.append((recipe, pair, build, ready, elapsed,
+                         result.returncode if result else "TIMEOUT", valid))
+            print(f"{recipe} pair={pair} build={build} whole_view_ready={ready:.3f}s "
+                  f"process_elapsed={elapsed:.1f}s {'PASS' if valid else 'FAIL'}", flush=True)
+            failed |= not valid
+
+summary = OUT / "cost-runs.csv"
+summary.write_text(
+    "recipe,pair,build,whole_view_ready_seconds,process_elapsed_seconds,exit_code,status\n" +
+    "".join(f"{recipe},{pair},{build},{ready:.6f},{elapsed:.3f},{code},"
+            f"{'PASS' if ok else 'FAIL'}\n"
+            for recipe, pair, build, ready, elapsed, code, ok in rows), encoding="utf-8")
+
+for recipe in ("surface-world", "floating-islands"):
+    by_build = {build: [row[3] for row in rows if row[0] == recipe and row[2] == build]
+                for build in BINARIES}
+    baseline = statistics.median(by_build["l32"])
+    current = statistics.median(by_build["l33"])
+    paired = []
+    for pair in range(1, 6):
+        values = {row[2]: row[3] for row in rows if row[0] == recipe and row[1] == pair}
+        paired.append((values["l33"] - values["l32"]) / values["l32"] * 100.0)
+    print(f"[L33CostSummary] recipe={recipe} pairs=5 median_l32_s={baseline:.3f} "
+          f"median_l33_s={current:.3f} median_change_pct={(current/baseline-1)*100.0:+.2f} "
+          f"paired_change_pct={','.join(f'{value:+.2f}' for value in paired)}", flush=True)
+
+print(f"[L33Cost] runs={len(rows)} status={'FAIL' if failed else 'PASS'} summary={summary}",
+      flush=True)
+raise SystemExit(1 if failed or len(rows) != 20 else 0)