feat: 添加矢量星武器和子弹功能

实现新的矢量星武器系统，包括武器卡片、子弹行为和粒子效果。主要功能包括：
- 添加VectorStarWeapon.gd武器脚本，支持多子弹发射和追踪目标
- 实现VectorStar.gd子弹脚本，包含初始冲刺和后续追踪逻辑
- 添加相关场景资源和配置
- 将新武器添加到公鸡角色的武器库中

scripts/Contents/Bullets/VectorStar.gd

@@ -0,0 +1,18 @@
+extends BulletBase
+class_name VectorStar
+
+var tracer: EntityBase = null
+var forwardTime: float = 1000
+var forwarded: bool = false
+
+func ai():
+	texture.rotation_degrees *= 1.1
+	PresetAIs.forward(self, rotation)
+	if timeLived() <= forwardTime:
+		speed = 10 * ((forwardTime - timeLived()) / forwardTime)
+	elif forwarded:
+		speed = (timeLived() - forwardTime) / 20
+	else:
+		forwarded = true
+		if is_instance_valid(tracer):
+			rotation = position.angle_to_point(tracer.position)