7cabda710d
- Replace the broken App::new() (which does not exist) with AppBuilder. - Strip it down to the PLAN's ~15-line target: no explicit winit/wgpu, AppHandler render() left empty (scene rendering still on the roadmap). - Verified: builds, opens a black window and runs the update->render->present loop until closed. - Update README/PLAN wording now that the simple example compiles (it still does not draw a scene).