feat(武器): 为火山武器添加幻影攻击功能

在火山武器的第4段攻击时发射多支火山幻影，造成额外伤害。修改了动画、伤害计算和武器描述，包括：
- 添加count和dmg5属性控制幻影数量和伤害
- 调整幻影动画效果和速度
- 更新武器描述模板和显示文本

scripts/Contents/Bullets/Volcano.gd

@@ -5,6 +5,9 @@ class_name Volcano
 @onready var anchor: Node2D = $%anchor
 
 var rotates: float = 0
+var count: int = 0
+var dmg5: float = 0
+var splitAngle: float = 10
 
 func register():
 	animator.speed_scale = launcher.fields.get(FieldStore.Entity.ATTACK_SPEED)
@@ -17,12 +20,14 @@ func ai():
 	)
 
 func generateShadow():
-	for i in BulletBase.generate(
-		ComponentManager.getBullet("VolcanoShadow"),
-		launcher,
-		textureSword.global_position,
-		anchor.global_rotation,
-		false, false, true, true
-	):
-		if i is VolcanoShadow:
-			i.baseDamage = baseDamage
+	var startAngle = rotation - deg_to_rad(count * splitAngle / 2)
+	for i in count:
+		for bullet in BulletBase.generate(
+			ComponentManager.getBullet("VolcanoShadow"),
+			launcher,
+			position,
+			startAngle + i * deg_to_rad(splitAngle),
+			false, false, true, true
+		):
+			if bullet is VolcanoShadow:
+				bullet.baseDamage = baseDamage * dmg5