fix: clip pockets and triangulation to boundary in plots — no visual crossovers

tools/adaptive-isogrid/src/brain/triangulation.py

@@ -224,8 +224,20 @@ def generate_triangulation(geometry, params, max_refinement_passes=3):
         cx = np.mean(all_pts[t, 0])
         cy = np.mean(all_pts[t, 1])
         centroid = Point(cx, cy)
-        # Keep if centroid is inside plate frame and outside keepouts
-        if inner_plate.contains(centroid) and not keepout_union.contains(centroid):
+        # Keep if centroid is inside plate frame and outside keepouts,
+        # AND all 3 vertices are inside the plate boundary (no crossovers)
+        if not inner_plate.contains(centroid):
+            continue
+        if keepout_union.contains(centroid):
+            continue
+        all_inside = True
+        for vi in t:
+            if not plate_poly.contains(Point(all_pts[vi])):
+                # Allow small tolerance (vertex on boundary is OK)
+                if not plate_poly.buffer(0.5).contains(Point(all_pts[vi])):
+                    all_inside = False
+                    break
+        if all_inside:
             keep.append(i)
 
     triangles = triangles[keep] if keep else np.empty((0, 3), dtype=int)