Add 3D mesh creation workflow

src/app/commands/draw.rs

@@ -454,6 +454,13 @@ impl OpenCADStudio {
                 self.tabs[i].active_cmd = Some(Box::new(new_cmd));
             }
 
+            "3DMESH" => {
+                use crate::modules::draw::draw::mesh3d::Mesh3dCommand;
+                let new_cmd = Mesh3dCommand::new();
+                self.command_line.push_info(&new_cmd.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(new_cmd));
+            }
+
             // 2D filled solid. Reached via SO / SOLID2D — the bare SOLID verb is
             // currently the shaded-display toggle (token collision tracked).
             "SOLID" | "SOLID2D" => {