A new empty design takes Units of new designs (#1283)

The empty design shown at launch, New on a design that is still empty, file.new and the blank design left when the last tab closes all take the Units of new designs preference. Opened files and the sample part keep their own units. Fixes #1205.

Co-authored-by: raythurman2386 <raythurman2386@users.noreply.github.com>

apps/solidcraft-web/src/main.rs

@@ -465,6 +465,9 @@ mod web {
                             app.session.mark_saved();
                         }
                         if !query().contains("sample") {
+                            // The empty design takes Units of new designs (#1205). The sample
+                            // part is built in millimetres and is left that way.
+                            solidcraft_ui_egui::prefs::apply_new_design(&mut app);
                             let rev = app.session.revision;
                             app.home.show(rev);
                         }

apps/solidcraft/src/main.rs

@@ -500,6 +500,11 @@ fn main() -> eframe::Result {
             for f in &files {
                 app.open_path_async(f);
             }
+            // No file and no sample: the empty design takes Units of new designs (#1205).
+            // An opened file and the sample part keep the units they were saved or built with.
+            if files.is_empty() && !sample {
+                solidcraft_ui_egui::prefs::apply_new_design(&mut app);
+            }
             // No design given: the start page (not when driven over the control channel, whose
             // clients expect the design view; `ui.home` shows it there).
             if files.is_empty() && !sample && control_port.is_none() {