refactor(子弹系统): 重构子弹伤害检测逻辑

将子弹伤害检测逻辑提取到BulletTool工具类中
新增SevenSoul子弹的初始属性和碰撞处理
调整hitbox位置并启用碰撞检测

scripts/Tools/BulletTool.gd

@@ -0,0 +1,13 @@
+class_name BulletTool
+
+static func fromArea(area: Area2D) -> BulletBase:
+	if area is BulletBase:
+		return area as BulletBase
+	else:
+		return null
+static func canDamage(bullet: BulletBase, target: EntityBase) -> bool:
+	if target.currentInvinsible: return false
+	if !bullet.canDamageSelf && target == bullet.launcher: return false
+	if !bullet.is_node_ready() && !GameRule.allowFriendlyFire:
+		if target.isPlayer() == bullet.launcher.isPlayer() and bullet.launcher.currentFocusedBoss != target: return false
+	return true