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/station/app/index.ludic

@@ -1,12 +1,10 @@
 # app/index.ludic - the app puts the program together: it sees the port and fills it
 module app uses clock
 bind Clock { now: fn game_hours }
-export state AppState {
-  g_hours: int = 30
+var g_hours: int = 30
+function game_hours() -> int {
+  return g_hours
 }
-function game_hours(app_st: AppState) -> int {
-  return app_st.g_hours
-}
-export function advance(app_st: mut AppState, h: int) -> void {
-  app_st.g_hours += h
+export function advance(h: int) -> void {
+  g_hours += h
 }