Holes on round faces from the app, and Flip for holes at sketch points (#980)

* Holes on round faces from the app, one hole per pick, and Flip for holes at sketch points (#967)

The Hole dialog takes any face: a hole on a round face drills against the face's normal where it
was picked, and its arrow shows that. A round face split at its seam is picked whole, but makes
one hole where it was clicked. Holes at sketch points get Flip (saved as flip in the hole's points,
under format 18), in the command and in the dialog.

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

* Holes at sketch points show their arrow: into the part, or away with Flip (#967)

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

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/canvas.rs

@@ -90,7 +90,30 @@ pub fn anchor(app: &SolveApp, d: &Dialog) -> Option<(Vec3, Option<Vec3>)> {
             let offset = if start.trim().is_empty() { 0.0 } else { app.session.doc.eval(start, ValueKind::Length).ok()? };
             (at + n * (from + offset), Some(n))
         }
-        Kind::Section { .. } | Kind::Hole { .. } | Kind::OffsetPlane { .. } | Kind::OffsetFaces { .. } => (at, normal),
+        // A hole on a curved face drills against the face's normal where it was picked.
+        Kind::Hole { .. } if matches!(first, Sel::Face { .. }) => {
+            (at, normal.or_else(|| solidcraft_engine::doc::hole_direction_at(&st, at).map(|d| -d)))
+        }
+        // Holes at sketch points go into the part the sketch touches (or away, flipped): the
+        // arrow shows which way.
+        Kind::Hole { .. } => {
+            let mut by_sketch: Vec<(u64, Vec<String>)> = Vec::new();
+            for x in &d.inputs.first()?.items {
+                if let Sel::SketchPoint { id } = x
+                    && let Some((sk, pid)) = id.split_once(':')
+                    && let Ok(sk) = sk.parse::<u64>()
+                {
+                    match by_sketch.iter_mut().find(|(s, _)| *s == sk) {
+                        Some((_, v)) => v.push(pid.to_string()),
+                        None => by_sketch.push((sk, vec![pid.to_string()])),
+                    }
+                }
+            }
+            let flip = d.extra.get("flip").and_then(serde_json::Value::as_bool).unwrap_or(false);
+            let dir = by_sketch.first().and_then(|(sk, ids)| solidcraft_engine::doc::sketch_hole_direction(&st, *sk, ids, flip));
+            (at, normal.or(dir.map(|d| -d)))
+        }
+        Kind::Section { .. } | Kind::OffsetPlane { .. } | Kind::OffsetFaces { .. } => (at, normal),
         // Fillet radii, chamfer distances and shell thickness grow into the body.
         Kind::Fillet { .. } | Kind::Shell { .. } => (at, normal.map(|n| -n)),
         Kind::Sheet(_) => (at, crate::dialogs_sheet::arrow(app, d).or(normal)),