planner: four-strate owner plan spawns (L66); pinned 2-strate regression fixture

- Core caps each passage mouth reach to its own strate's usable content band (owner
  DA_Strate1 exports ReachMax=5000 owner voxels, which put the SW->FI lower mouth 79.5 m
  below FI, inside TN).
- Unreal adapter: SW route search keeps the old 64 m candidates first, then a bounded
  single-mouth search with shorter lengths; logs candidate/rejection counts.
- Internal-chain passage floor/support tweaks (only with >2 strates): ripple 1-2 4.78->2.90 cm,
  2-3 3.57->0.10 cm. Interfaces still 0/3 walkable (59/3/2 unsupported).
- verify.py: legacy tiers use Standalone/data/regression/owner_world_2strate_l61.json; new
  four-strate stage reads its expectations from owner_world.json (currently red on interfaces).
- Unreal trace L14 vs HEAD, same assets (16-chunk FlatPlain): 12.20 vs 12.56 worker-s; no x2.

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

Standalone/Research/WorldAssemblerM3/Linux37/RunCostL37.py

@@ -2,6 +2,7 @@
 """Run five interleaved whole-view cost pairs against the L36 Clang binary."""
 import csv
 import math
+import os
 import re
 import statistics
 import subprocess
@@ -10,6 +11,8 @@ from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[4]
 OUT = ROOT / "Saved/Linux/l37"
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
 BINARIES = {
     "l36": ROOT / "Saved/Linux/l36/bin/VoxelForgeCoreHeadless-l36-final-clang",
     "l37": OUT / "bin/VoxelForgeCoreHeadless-l37-final-clang",
@@ -30,7 +33,7 @@ for recipe in ("surface-world", "floating-islands"):
             command = [
                 "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
                 "timeout", "900s", str(BINARIES[build]),
-                str(ROOT / "Standalone/data/owner_world.json"),
+                str(OWNER),
                 "--workers=12", "--world-assembler-prototype", "--stream-benchmark",
                 "--stream-pipeline", "--force-generate", "--clip-radius=3",
                 "--max-clip-level=8", "--max-level=-1", f"--recipe={recipe}",