feat: 添加无敌状态和自定义波次逻辑

- 为EntityBase添加currentInvinsible属性控制无敌状态
- 修改BulletBase.gd在命中时检查目标无敌状态
- 在World.tscn中设置rooster初始为无敌状态
- 添加Wave.gd自定义波次启动逻辑
- 修复currentFocusedBoss未初始化时的空指针问题

components/Characters/KukeMC.tscn

@@ -30,6 +30,9 @@ size = Vector2(150, 150)
 script = ExtResource("2_s2dg5")
 displayName = "酷可mc"
 
+[node name="collect" parent="sounds" index="4"]
+stream = null
+
 [node name="texture" parent="." index="2"]
 sprite_frames = SubResource("SpriteFrames_1c0ui")
 animation = &"walk"

components/Scenes/World.tscn

@@ -103,3 +103,4 @@ shape = SubResource("CircleShape2D_4hkht")
 polygon = PackedVector2Array(-2419, 1803, 2429, 1825, 2392, -366, 2867, -318, 2723, 2241, -2879, 2193, -2797, -2582, 2959, -2528, 2858, -347, 2420, -337, 2441, -1834, -2438, -1792)
 
 [node name="rooster" parent="." groups=["players"] instance=ExtResource("3_5ui6q")]
+currentInvinsible = true