refactor(skill): 清理旧技能资源并更新攻击预制体

1.  删除废弃的技能图片、动画剪辑和旧的攻击预制体
2.  新增aw1/aw2/aw3/b3新攻击预制体
3.  调整现有攻击预制体的尺寸、缩放和精灵帧引用
4.  更新fb-2动画和预制体的配置

assets/resources/game/skill/atk/b3.prefab.meta

@@ -0,0 +1,13 @@
+{
+  "ver": "1.1.50",
+  "importer": "prefab",
+  "imported": true,
+  "uuid": "e9af1f49-ec92-4dc2-9312-5730e0838454",
+  "files": [
+    ".json"
+  ],
+  "subMetas": {},
+  "userData": {
+    "syncNodeName": "b3"
+  }
+}