wip(0.S2): migrate - a var nothing writes becomes a let; a state is keyed by its module, directory or program, so every program's plan agrees; paths normalized; program states named SceneDemoState / scene_demo_st; the LSP reads state, mut and entry/handler parameters

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/modules/private_twins.ludic

@@ -9,7 +9,7 @@ program PrivateTwins {
   function seed() -> int {
     return 7
   }
-  entry (shop_st: ShopState, weather_st: WeatherState) {
-    print(`{shop_seed(shop_st)} {weather_seed(weather_st)} {seed()}`)
+  entry {
+    print(`{shop_seed()} {weather_seed()} {seed()}`)
   }
 }