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/doc/src/eval.rs

@@ -2050,6 +2050,16 @@ fn hole_reaches(st: &ModelState, p: Vec3, d: Vec3, ahead: bool) -> bool {
 /// from the plane's normal) if any spot touches material that way, else `+n` if any spot touches
 /// material that way. With no touching on either side it goes by the nearest body ahead: `-n` if
 /// any spot has a body ahead that way, else `+n` if any has, else `-n`.
+/// The way holes at these points of a sketch drill (see [`sketch_hole_dir`]), flipped or not.
+/// None when the sketch or a point is not there.
+pub fn sketch_hole_direction(st: &ModelState, sketch: u64, ids: &[String], flip: bool) -> Option<Vec3> {
+    let ss = st.sketch(sketch)?;
+    let spots: Vec<Vec3> =
+        ids.iter().map(|id| ss.sketch.points.iter().find(|p| &p.id == id).map(|p| ss.plane.to_world(p.pos))).collect::<Option<_>>()?;
+    let dir = sketch_hole_dir(st, &spots, ss.plane.normal());
+    Some(if flip { -dir } else { dir })
+}
+
 fn sketch_hole_dir(st: &ModelState, spots: &[Vec3], n: Vec3) -> Vec3 {
     let down = -n;
     let any = |d: Vec3, ahead: bool| spots.iter().any(|p| hole_reaches(st, *p, d, ahead));
@@ -2077,6 +2087,7 @@ fn hole_spots(st: &ModelState, f: &Feature) -> Result<(Vec<Vec3>, Vec3)> {
                 v.push(ss.plane.to_world(p.pos));
             }
             let dir = sketch_hole_dir(st, &v, ss.plane.normal());
+            let dir = if sp.flip { -dir } else { dir };
             (v, dir)
         }
         None => {
@@ -2123,6 +2134,7 @@ fn hole_spots_raw(st: &ModelState, f: &Feature) -> Result<(Vec<Vec3>, Vec3)> {
             let v: Vec<Vec3> =
                 sp.ids.iter().filter_map(|id| ss.sketch.points.iter().find(|p| &p.id == id)).map(|p| ss.plane.to_world(p.pos)).take(10_000).collect();
             let dir = sketch_hole_dir(st, &v, ss.plane.normal());
+            let dir = if sp.flip { -dir } else { dir };
             Ok((v, dir))
         }
         None => {