(client) feat:实现掉落物，UI显示，维度

Client/Assets/Scripts/Entity/EntityHitEventArgs.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Entity
+{
+    public class EntityHitEventArgs : EventArgs
+    {
+        public Entity AttackedEntity { get; }      // 被攻击的实体
+        public Entity AttackerEntity { get; }      // 攻击者
+        public int DamageDealt { get; }             // 这次攻击造成的实际伤害
+        public float CurrentHealth { get; }         // 攻击后的当前生命值
+        public float MaxHealth { get; }             // 最大生命值
+        public bool WasFatal { get; }               // 这次攻击是否致命（导致死亡）
+
+        public EntityHitEventArgs(Entity attacked, Entity attacker, int damage, float currentHealth, float maxHealth, bool wasFatal)
+        {
+            AttackedEntity = attacked;
+            AttackerEntity = attacker;
+            DamageDealt = damage;
+            CurrentHealth = currentHealth;
+            MaxHealth = maxHealth;
+            WasFatal = wasFatal;
+        }
+    }
+
+}