fix: a lenient parameter boundary found across a seam is not used; record seed 81 (#1003)

#970's lenient retry of a face's parameter boundary searches the whole surface as a last resort; on robustness seed 20 it found an edge's points across a cylinder's seam, half a turn apart, and the Cut failed. A lenient boundary whose points jump half the parameter range or more is refused, and the face is left undivided as before (#970's elbows step at most a fifth of the range). Seed 81's volume moved by 0.1 mm3 with #952's hole direction; recorded.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

vendor/truck-shapeops/src/transversal/divide_face/mod.rs

@@ -71,6 +71,18 @@ where
         vec.append(&mut add?);
         Some(vec)
     })?;
+    // SolidCraft: a lenient boundary whose points jump half the parameter range or more has been
+    // found across a periodic surface's seam by the whole-surface search (on a cylinder the
+    // points of one edge landed at both ends of its angle): it would divide the face wrongly, so
+    // the face is left undivided as before.
+    if lenient {
+        let (u, v) = surface.try_range_tuple();
+        let half = |r: Option<(f64, f64)>| r.map_or(f64::INFINITY, |(a, b)| (b - a).abs() / 2.0);
+        let (hu, hv) = (half(u), half(v));
+        if vec.windows(2).any(|w| (w[1].x - w[0].x).abs() >= hu || (w[1].y - w[0].y).abs() >= hv) {
+            return None;
+        }
+    }
     Some(PolylineCurve(vec))
 }