Add SoundEffect audio system (ScriptableObject-based) with test assets

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Scripts/Audio/SoundEffectOptions.cs

@@ -0,0 +1,32 @@
+using UnityEngine;
+using UnityEngine.Audio;
+
+namespace Prototype
+{
+    public struct SoundEffectOptions
+    {
+        public AudioMixerGroup audioMixerGroup;
+
+        public float? volume;
+        public float? volumeMultiplier;
+        public float GetVolume() => (volume ?? 1) * (volumeMultiplier ?? 1);
+
+        public float? pitch;
+        public float GetPitch() => pitch ?? 1;
+
+        public bool? loop;
+        public bool GetLoop() => loop ?? false;
+
+        public Vector2? distanceRange;
+        public Vector2 GetDistanceRange() => distanceRange ?? new(30, 200);
+
+        public Vector2? fade;
+        public Vector2 GetFade() => fade ?? new();
+
+        public bool? destroyOnLoad;
+        public bool ShouldDestroyOnLoad() => destroyOnLoad ?? true;
+
+        public float? delay;
+        public float GetDelay() => delay ?? 0;
+    }
+}