Add browser debugging support

src/main.ts

@@ -10,9 +10,24 @@ import './styles/global.css';
 declare global {
   interface Window {
     __HEROS_GAME__?: Phaser.Game;
+    __HEROS_DEBUG__?: HerosDebugApi;
   }
 }
 
+type DebugBattleScene = Phaser.Scene & {
+  getDebugState?: () => unknown;
+  toggleDebugOverlay?: () => void;
+};
+
+type HerosDebugApi = {
+  game: Phaser.Game;
+  activeScenes: () => string[];
+  battle: () => unknown;
+  goToBattle: () => void;
+  scene: (key: string) => Phaser.Scene | undefined;
+  toggleBattleOverlay: () => void;
+};
+
 const config: Phaser.Types.Core.GameConfig = {
   type: Phaser.AUTO,
   parent: 'game',
@@ -32,4 +47,24 @@ const game = new Phaser.Game(config);
 
 if (import.meta.env.DEV) {
   window.__HEROS_GAME__ = game;
+  window.__HEROS_DEBUG__ = createDebugApi(game);
+  console.info('[Heros Debug] Use window.__HEROS_DEBUG__.battle() or press F9 in battle.');
+}
+
+function createDebugApi(game: Phaser.Game): HerosDebugApi {
+  const scene = (key: string) => game.scene.getScene(key);
+  const battleScene = () => scene('BattleScene') as DebugBattleScene | undefined;
+
+  return {
+    game,
+    activeScenes: () => game.scene.getScenes(true).map((activeScene) => activeScene.scene.key),
+    battle: () => battleScene()?.getDebugState?.() ?? { active: false, reason: 'BattleScene is not active yet.' },
+    goToBattle: () => {
+      game.scene.start('BattleScene');
+    },
+    scene,
+    toggleBattleOverlay: () => {
+      battleScene()?.toggleDebugOverlay?.();
+    }
+  };
 }