Sweep: orientation, twist and end scale (#1269)

Part of #771 and #772. solid.sweep and surface.sweep take orientation (perpendicular, parallel or a direction), twist (up to 4 turns) and end scale (0.01 to 100), applied about the profile's normal through the path's start; default options run the old sweep, so existing sweeps are unchanged. New fields are optional, left out when unset and noted under format 21; twist and scale are model parameters. Both sweep dialogs get Orientation, Twist and End Scale rows; labels in every catalog. Checked on main + this branch: cargo check --workspace, kernel/engine/UI sweep tests, the doc suite and the robustness goldens.

crates/engine/src/tests.rs

@@ -769,6 +769,9 @@ fn hostile_params_never_panic() {
         "filter",
         "kind",
         "prefix",
+        "orientation",
+        "twist",
+        "scale",
     ];
     // Commands are independent; worker threads take them one at a time (their costs vary a lot).
     let ids: Vec<&str> = command_specs()