feat: edge flanges with their own angle and height per edge (#447)

One edge flange feature gave all its flanges one height and one angle. A
part whose flanges lean differently took one feature per angle, and
flanges of separate features don't close toward each other, so its
corners stayed open.

- sheet.flange (edge): an entry of `edges` is a point [x, y, z] as before,
  or {point, angle?, height?} whose angle and height (expressions, checked
  like the feature's) replace the feature's for that edge. Bad input is
  refused with the edge named. Before, the object form was read for its
  point and the rest was ignored without a word.
- The feature stores its edges as FlangeEdge. An edge without values of
  its own is written as the plain point it always was, so designs without
  them are read and written as before; an unknown key in an edge is
  refused, not dropped.
- The edges' values are feature inputs of their own (Edge angle, Edge
  height, after the feature's), so parameters, renames and
  parameters.change reach them. timeline.edit names the edges again when
  it changes them, so each value stays with its edge.
- SheetBody::add_flanges_each trims every edge by its own setback and
  adds the flanges. The corners between them close as between equal
  flanges: the closing already works from the two flanges it joins (each
  one's fold and leg), so the flat pattern follows by hand from the
  angles, the heights and the rule (the tests derive it).
- The Flange dialog shows a row per picked edge with an angle and a
  height box (empty: the dialog's value) once more than one edge is
  picked, and brings them back on Edit Feature.

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

crates/ui-egui/src/dialogs_sheet_tests.rs

@@ -318,3 +318,65 @@ fn pocket_depth_labels_follow_inches_without_changing_flat_data() {
     assert_eq!(super::pocket_label(&app, &json!({"side":"top","depth_mm":25.4*0.1234})).as_deref(), Some("Top pocket: 0.1234 in deep"));
     assert!(super::pocket_label(&app, &json!({"side":"top","depth_mm":-1})).is_none());
 }
+
+/// Edges with an angle and/or a height of their own: the texts of the dialog's rows per edge
+/// become `{point, angle?, height?}` edges while the others stay plain points; Edit Feature
+/// brings them back and rebuilds the same flanges.
+#[test]
+fn edge_flanges_can_have_an_angle_and_a_height_of_their_own() {
+    let mut app = plate();
+    app.run("sheet.flange", json!({"sketch": "Base"})).unwrap();
+    let edges: Vec<Sel> = [[50.0, 0.0, 2.5], [50.0, 60.0, 2.5], [0.0, 30.0, 2.5], [100.0, 30.0, 2.5]]
+        .iter()
+        .filter_map(|p| edge_sel(&app.session, Vec3::new(p[0], p[1], p[2])))
+        .collect();
+    assert_eq!(edges.len(), 4);
+    let point = |i: usize| if let Sel::Edge { point, .. } = &edges[i] { *point } else { Vec3::ZERO };
+    app.session.selection = edges.clone();
+    app.start("sheet.flange");
+    let mut d = app.dialog.clone().unwrap();
+    if let Kind::Sheet(Sm::Flange { height, angle, own, .. }) = &mut d.kind {
+        *height = "20 mm".into();
+        *angle = "75 deg".into();
+        // The second edge: its own angle; the fourth: both; the third: texts left blank.
+        own.push((point(1), "100 deg".into(), String::new()));
+        own.push((point(3), "90 deg".into(), "15 mm".into()));
+        own.push((point(2), "  ".into(), String::new()));
+    }
+    let c = apply_commands(&app, &d).unwrap();
+    assert_eq!(
+        c[0].1["edges"],
+        json!([pt(point(0)), {"point": pt(point(1)), "angle": "100 deg"}, pt(point(2)), {"point": pt(point(3)), "angle": "90 deg", "height": "15 mm"}]),
+        "no text or a blank one: a plain point"
+    );
+    run_all(&mut app, c);
+    let bends = app.session.execute("sheet.flat_pattern", &json!({})).unwrap()["bends"].clone();
+    let angles: Vec<f64> = bends.as_array().unwrap().iter().map(|b| b["angle_deg"].as_f64().unwrap().round()).collect();
+    assert_eq!(angles, [75.0, 100.0, 75.0, 90.0], "{bends}");
+    assert!(app.session.model.results.iter().all(|r| r.error.is_none()), "{:?}", app.session.model.results);
+    // Edit Feature: the edges and their own values come back, and OK rebuilds the same part.
+    let f = app.session.doc.features.last().unwrap().clone();
+    let mut e = edit_dialog(&app, f.id, None).unwrap();
+    assert_eq!(e.inputs[0].items.len(), 4);
+    let Kind::Sheet(Sm::Flange { own, .. }) = &e.kind else { panic!("not a flange dialog") };
+    assert_eq!(own.len(), 2, "{own:?}");
+    assert!(own.iter().any(|o| o.0.dist(point(1)) < 1e-9 && o.1 == "100 deg" && o.2.is_empty()), "{own:?}");
+    assert!(own.iter().any(|o| o.0.dist(point(3)) < 1e-9 && o.1 == "90 deg" && o.2 == "15 mm"), "{own:?}");
+    let volume = |app: &mut SolveApp| app.session.execute("inspect.measure", &json!({})).unwrap()["total"]["volume_mm3"].as_f64().unwrap();
+    let before = volume(&mut app);
+    let c = apply_commands(&app, &e).unwrap();
+    assert_eq!(c[0].0, "timeline.redefine");
+    assert_eq!(c[0].1["params"]["edges"][1], json!({"point": pt(point(1)), "angle": "100 deg"}));
+    assert_eq!(c[0].1["params"]["edges"][3]["height"], "15 mm");
+    run_all(&mut app, c);
+    let after = volume(&mut app);
+    assert!((after - before).abs() < 1e-6 * before, "{after} vs {before}");
+    // Taking edges out of the selection leaves each value with its edge.
+    e.inputs[0].items.remove(2);
+    e.inputs[0].items.remove(0);
+    let c = apply_commands(&app, &e).unwrap();
+    assert_eq!(
+        c[0].1["params"]["edges"],
+        json!([{"point": pt(point(1)), "angle": "100 deg"}, {"point": pt(point(3)), "angle": "90 deg", "height": "15 mm"}])
+    );
+}