refactor(modules): rename home module to draw, restore first-tab order

The Home tab was already titled "Draw"; rename the module to match:
folder modules/home → modules/draw, HomeModule → DrawModule, id "home"
→ "draw". The inner draw/ command folder is kept (modules::draw::draw).

Update build.rs PRIORITY ("home" → "draw") so the tab returns to the
front of the ribbon; registry.rs regenerates accordingly.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/modules/registry.rs

@@ -7,7 +7,7 @@ use crate::modules::CadModule;
 /// Called once at startup by `Ribbon::new()`.
 pub fn all_modules() -> Vec<Box<dyn CadModule>> {
 	vec![
-		Box::new(super::home::HomeModule),
+		Box::new(super::draw::DrawModule),
 		Box::new(super::model::ModelModule),
 		Box::new(super::insert::InsertModule),
 		Box::new(super::annotate::AnnotateModule),