feat(武器系统): 添加核弹武器及相关资源

实现核弹武器功能，包括：
- 添加核弹控制器武器脚本和场景
- 实现核弹子弹逻辑和爆炸效果
- 添加相关图片、音效资源
- 更新角色武器库包含核弹
- 调整武器名称颜色配置

scripts/Contents/Weapons/NuclearBomb.gd

@@ -0,0 +1,14 @@
+@tool
+extends Weapon
+
+func update(to: int, origin: Dictionary, _entity: EntityBase):
+	origin["atk"] += 25 * to * soulLevel
+	origin["radius"] += 20 * to * soulLevel
+	return origin
+func attack(entity: EntityBase):
+	var weaponPos = entity.findWeaponAnchor("normal")
+	for j in BulletBase.generate(preload("res://components/Bullets/NuclearBomb.tscn"), entity, weaponPos, weaponPos.angle_to_point(get_global_mouse_position())):
+		var bullet: NuclearBomb = j
+		bullet.damage = readStore("atk")
+		bullet.radius = readStore("radius")
+	return true