fix: reset game state flags in init() so input works on level transitions

Phaser constructor only runs once; init() runs on every scene.start().
handleLevelComplete() was setting isPaused=true/inputEnabled=false which
persisted into subsequent levels, freezing player input.

src/game/scenes/Game.js

@@ -32,9 +32,16 @@ export class Game extends Phaser.Scene {
     }
 
     init(data) {
-        // Initialize with data passed from previous scene
         this.currentLevel = data.level || 1;
         this.livesRemaining = data.lives || 3;
+        // Reset state flags (constructor only runs once in Phaser)
+        this.inputEnabled = true;
+        this.isPaused = false;
+        this.isFinalLevel = false;
+        this.inputCooldown = 0;
+        this.guards = [];
+        this.detectionPopup = null;
+        this.finalLevelMessage = null;
     }
 
     create() {