feat(武器): 增强核弹效果并添加警告动画

- 提升核弹的攻击力和爆炸半径
- 为核弹添加逐渐扩大的红色警告环
- 改进核爆炸效果，调整粒子参数和震动强度
- 新增填充环着色器用于警告效果

scripts/Contents/Bullets/NuclearBomb.gd

@@ -3,6 +3,7 @@ class_name NuclearBomb
 
 @onready var label: Label = $"%label"
 @onready var anchor: Node2D = $"%anchor"
+@onready var warn: ShaderStage = $"%warn"
 
 var countdown = 10000
 var radius = 500
@@ -14,11 +15,13 @@ func spawn():
 func ai():
 	speed *= 0.99
 	PresetBulletAI.forward(self, rotation)
-	label.text = "NUCLEAR WARNING %.1f" % ((countdown - timeLived()) / 1000)
 	if timeLived() > countdown:
 		tryDestroy()
+	else:
+		warn.size = Vector2.ONE * 2 * radius * (timeLived() / countdown)
+		label.text = "NUCLEAR WARNING %.1f" % ((countdown - timeLived()) / 1000)
 func destroy(_b):
 	EffectController.create(preload("res://components/Effects/NuclearExplosion.tscn"), global_position).shot()
 	hitbox.disabled = false
-	CameraManager.shake(5000, 250, func(_c, t, r): return t * r) # 震屏强度随进度递减
+	CameraManager.shake(5000, 500, func(_c, t, r): return t * r) # 震屏强度随进度递减
 	await TickTool.frame(5)