(client)feat:实现子弹定义以及生成，实现初始化动画，实现血条 (#43)

Co-authored-by: zzdxxz <2079238449@qq.com>
Co-committed-by: zzdxxz <2079238449@qq.com>

Client/Assets/Scripts/Entity/Bullet.cs

@@ -0,0 +1,66 @@
+using System;
+using Base;
+using Data;
+using Prefab;
+using UnityEngine;
+
+namespace Entity
+{
+    public class Bullet : Entity
+    {
+        public Entity bulletSource;
+        public float lifeTime = 10;
+        
+        public override void SetTarget(Vector3 pos)
+        {
+            base.SetTarget(pos);
+            RotateTransformToDirection(transform, direction);
+        }
+
+        protected override void AutoBehave()
+        {
+            TryMove();
+            lifeTime-=Time.deltaTime;
+            if (lifeTime <= 0)
+            {
+                Kill();
+            }
+        }
+
+        private void OnTriggerEnter2D(Collider2D other)
+        {
+            var entity = other.GetComponent<Entity>();
+            if (!entity || entity == bulletSource) return;
+            if (Managers.AffiliationManager.Instance.GetRelation(bulletSource.affiliation, entity.affiliation) != Relation.Friendly)
+            {
+                entity.OnHit(this);
+            }
+            else if (Setting.Instance.CurrentSettings.friendlyFire)
+            {
+                entity.OnHit(this);
+            }
+            else
+            {
+                return; // 如果是友好关系且不允许友军伤害，则不处理
+            }
+            attributes.health -= 1;
+        }
+
+        // 旋转对象到指定方向
+        public static void RotateTransformToDirection(Transform transform, Vector3 targetDirection)
+        {
+            // 确保目标方向不是零向量
+            if (targetDirection == Vector3.zero)
+                return;
+
+            // 计算当前向上方向与目标方向之间的角度
+            float angle = Mathf.Atan2(targetDirection.y, targetDirection.x) * Mathf.Rad2Deg;
+
+            // 调整角度，因为默认贴图向上是0度，而Atan2计算的是相对于x轴的角度
+            angle -= 90f;
+
+            // 应用旋转
+            transform.rotation = Quaternion.Euler(0f, 0f, angle);
+        }
+    }
+}