feat: add StateManager.dump() and expose window.__sm for debugging

- StateManager.dump(): console.table formatted dump of variables, flags, history
- window.__sm: exposes engine.stateManager in dev mode for console inspection

engine/core/StateManager.ts

@@ -91,4 +91,12 @@ export class StateManager {
     this.flags = new Set(data.flags)
     this.history = [...data.history]
   }
+
+  dump() {
+    console.group('StateManager')
+    console.table(this.variables)
+    console.log('flags:', [...this.flags])
+    console.table(this.history)
+    console.groupEnd()
+  }
 }