feat(card): 实现英雄卡升级标识与交互优化

1. 新增升级专用动画资源与up_icon_node节点
2. 重构等级显示逻辑，升级卡显示前后等级
3. 调整召唤按钮文案为"升级"或"招募"适配场景
4. 移除无用的getLvColor导入与旧的层级控制逻辑

assets/resources/gui/anim/card_lv_up.anim.meta

@@ -0,0 +1,13 @@
+{
+  "ver": "2.0.3",
+  "importer": "animation-clip",
+  "imported": true,
+  "uuid": "c2d432a6-b24f-4511-b84f-87a02f9787c3",
+  "files": [
+    ".cconb"
+  ],
+  "subMetas": {},
+  "userData": {
+    "name": "card_lv_up"
+  }
+}