Add animated combat growth rewards

src/game/audio/SoundDirector.ts

@@ -90,6 +90,21 @@ class SoundDirector {
     window.setTimeout(() => this.playTone(450, 0.08, 0.028, 'sine'), 70);
   }
 
+  playGrowthTick() {
+    if (this.playEffect('exp-gain', { volume: 0.18, rate: 1.12, stopAfterMs: 360 })) {
+      return;
+    }
+
+    this.playTone(620, 0.05, 0.018, 'triangle');
+  }
+
+  playLevelUp() {
+    this.playEffect('exp-gain', { volume: 0.42, rate: 1.08, stopAfterMs: 820 });
+    this.playTone(520, 0.08, 0.035, 'triangle');
+    window.setTimeout(() => this.playTone(720, 0.09, 0.04, 'triangle'), 82);
+    window.setTimeout(() => this.playTone(980, 0.12, 0.034, 'sine'), 168);
+  }
+
   playEffect(key: string, options: PlayEffectOptions = {}) {
     if (!this.started || this.muted) {
       return false;