Playertest: scene/script system refactor and Wii ABI fix

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/init.lua

@@ -1,8 +1,3 @@
-module('input')
-module('platform')
-module('scene')
-module('locale')
-
 -- Default Input bindings.
 if PSP then
   inputBind("up", INPUT_ACTION_UP)
@@ -77,5 +72,4 @@ else
   print("Unknown platform, no default input bindings set.")
 end
 
--- Hand off to initial scene.
-sceneSet('test/scene.lua')
+Scene.set('scenes/cube.lua')