fix: add try/except + debug logging around sandbox extraction

.gitignore

@@ -138,3 +138,4 @@ docs/generated/
 
 # Malformed filenames (Windows path used as filename)
 C:*
+*.gitmodules

tools/adaptive-isogrid/src/nx/extract_sandbox.py

@@ -490,23 +490,39 @@ def main():
     # Extract each sandbox
     for sandbox_id, body, face in sandbox_entries:
         lister.WriteLine(f"\n--- Extracting {sandbox_id} ---")
-        geom = extract_sandbox_geometry(
-            face=face,
-            body=body,
-            sandbox_id=sandbox_id,
-            lister=lister,
-            chord_tol_mm=0.1,
-        )
+        try:
+            # Debug: print face info
+            lister.WriteLine(f"[extract_sandbox] Face type: {type(face).__name__}")
+            try:
+                loops = face.GetLoops()
+                lister.WriteLine(f"[extract_sandbox] Loops: {len(loops)}")
+                for li, loop in enumerate(loops):
+                    edges = loop.GetEdges()
+                    lister.WriteLine(f"[extract_sandbox]   Loop {li}: {len(edges)} edges")
+            except Exception as exc:
+                lister.WriteLine(f"[extract_sandbox] GetLoops failed: {exc}")
 
-        out_path = os.path.join(output_dir, f"geometry_{sandbox_id}.json")
-        with open(out_path, "w") as f:
-            json.dump(geom, f, indent=2)
-        lister.WriteLine(f"[extract_sandbox] Wrote: {out_path}")
+            geom = extract_sandbox_geometry(
+                face=face,
+                body=body,
+                sandbox_id=sandbox_id,
+                lister=lister,
+                chord_tol_mm=0.1,
+            )
 
-        # Summary
-        lister.WriteLine(f"  outer_boundary: {len(geom['outer_boundary'])} points")
-        lister.WriteLine(f"  inner_boundaries: {geom['num_inner_boundaries']}")
-        lister.WriteLine(f"  thickness: {geom['thickness']}")
+            out_path = os.path.join(output_dir, f"geometry_{sandbox_id}.json")
+            with open(out_path, "w") as f:
+                json.dump(geom, f, indent=2)
+            lister.WriteLine(f"[extract_sandbox] Wrote: {out_path}")
+
+            # Summary
+            lister.WriteLine(f"  outer_boundary: {len(geom['outer_boundary'])} points")
+            lister.WriteLine(f"  inner_boundaries: {geom['num_inner_boundaries']}")
+            lister.WriteLine(f"  thickness: {geom['thickness']}")
+        except Exception as exc:
+            import traceback
+            lister.WriteLine(f"[extract_sandbox] ERROR extracting {sandbox_id}: {exc}")
+            lister.WriteLine(traceback.format_exc())
 
     lister.WriteLine("\n" + "=" * 60)
     lister.WriteLine(f"  Done — {len(sandbox_entries)} sandbox(es) exported")