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 <[email protected]>

src/modules/mod.rs

@@ -25,7 +25,7 @@ pub use ocs_plugin_api::ribbon::{
 // ── Module declarations ───────────────────────────────────────────────────
 
 pub mod annotate;
-pub mod home;
+pub mod draw;
 pub mod insert;
 pub mod model;
 pub mod layout;