wip(assembler): round L19 -- strate ceilings closed at every LOD; ledges diagnosed

The shared boundary-cap path now emits a cap wherever the field is solid just below a strate's
configured top (it previously required a solid-to-air crossing there) and checks a 5x5 perimeter
grid before suppressing a fallback cap. Strict audit: 0 misses / 0 edge gaps, LOD0-8.
farHorizonVersion 3 -> 4. SurfaceWorld LOD0-2, full detail and exact queries unchanged; 28/28
matrix plus 14/14 crossing; route parity and proofs pass.
Ledges: the lower stratum's terrain at the FI/SW interface, seen through the FI void, sampled at
0.5/1/2 m at LOD1-3 (up to 1.5 m / 7.7 m ring steps). Fix deferred to the units/layers round.

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

Standalone/Research/WorldAssemblerM3/Linux19/CheckL19Hashes.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""Check deterministic matrices and protected SurfaceWorld identities against L14."""
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[4]
+MATRIX = ROOT / "Saved/Linux/l19-matrix"
+CROSSING = ROOT / "Saved/Linux/l19-crossing"
+ROW = re.compile(r"^\[Pipeline(?:FullDetailHash|WholeViewHash|LODHash|ExactQueryHash)\].*$", re.M)
+LOD = re.compile(r"^\[PipelineLODHash\] lod=(\d+) .*$", re.M)
+failed = []
+
+
+def stable_rows(path):
+    rows = ROW.findall(path.read_text(encoding="utf-8", errors="replace"))
+    full = next((row for row in rows if row.startswith("[PipelineFullDetailHash]")), None)
+    exact = next((row for row in rows if row.startswith("[PipelineExactQueryHash]")), None)
+    lods = {int(match.group(1)): match.group(0) for match in LOD.finditer(
+        path.read_text(encoding="utf-8", errors="replace"))}
+    return rows, full, exact, {level: lods.get(level) for level in range(3)}
+
+
+for compiler in ("clang-off", "gcc-default"):
+    baseline_name = "clang-off" if compiler == "clang-off" else "gcc-default"
+    baseline = ROOT / f"Saved/Linux/l14-final-hash-sw-{baseline_name}-w12-r5.log"
+    expected = stable_rows(baseline)
+    logs = sorted(MATRIX.glob(f"surface-world-{compiler}-w*-r*.log"))
+    if len(logs) != 7:
+        failed.append(f"matrix {compiler}: expected 7 rows, found {len(logs)}")
+    for path in logs:
+        actual = stable_rows(path)
+        if len(actual[0]) != 12 or actual[1:] != expected[1:]:
+            failed.append(f"protected SurfaceWorld mismatch: {path.name}")
+
+    crossing_baseline_name = "clang" if compiler == "clang-off" else "gcc"
+    crossing_baseline = ROOT / f"Saved/Linux/l14-final-crossing-24m-{crossing_baseline_name}-w12.log"
+    expected_crossing = stable_rows(crossing_baseline)
+    crossing_logs = sorted(CROSSING.glob(f"{compiler}-w*-r*.log"))
+    if len(crossing_logs) != 7:
+        failed.append(f"crossing {compiler}: expected 7 rows, found {len(crossing_logs)}")
+    for path in crossing_logs:
+        actual = stable_rows(path)
+        if len(actual[0]) != 12 or actual[1:] != expected_crossing[1:]:
+            failed.append(f"protected crossing identity mismatch: {path.name}")
+
+print(f"[L19ProtectedHashGate] SurfaceWorld LOD0-2, full-detail, and exact query hashes "
+      f"result={'FAIL' if failed else 'PASS'}")
+for failure in failed:
+    print(f"[L19HashMismatch] {failure}")
+raise SystemExit(1 if failed else 0)