refactor(map): 重构装备卡槽管理与节点挂载逻辑

1.  移除HeroBoxComp中未使用的ebars_node属性
2.  重构EBox.load方法，支持自定义父节点并更新注释
3.  重构MissEquipComp：
    - 移除无用的BoxSet导入和硬编码槽位坐标
    - 使用ebars_node子节点动态生成槽位
    - 修改装备挂载逻辑，将装备挂载到对应ebar子节点而非直接设置位置
    - 更新相关注释与日志提示
4.  调整mission.prefab的UI布局参数与绑定节点

assets/resources/gui/element/mission.prefab

@@ -1906,7 +1906,7 @@
     "_lpos": {
       "__type__": "cc.Vec3",
       "x": 306.634,
-      "y": 651.253,
+      "y": 216.64,
       "z": 0
     },
     "_lrot": {
@@ -2425,7 +2425,7 @@
     "_left": -8.317000000000007,
     "_right": -6.6340000000000146,
     "_top": 89.63,
-    "_bottom": 596.253,
+    "_bottom": 161.64,
     "_horizontalCenter": 0,
     "_verticalCenter": 0,
     "_isAbsLeft": true,
@@ -7013,7 +7013,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": -315,
+      "x": -310,
       "y": 0,
       "z": 0
     },
@@ -7292,7 +7292,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": -235,
+      "x": -220,
       "y": 0,
       "z": 0
     },
@@ -7571,7 +7571,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": -155,
+      "x": -130,
       "y": 0,
       "z": 0
     },
@@ -7850,7 +7850,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": -75,
+      "x": -40,
       "y": 0,
       "z": 0
     },
@@ -8129,7 +8129,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": 5,
+      "x": 50,
       "y": 0,
       "z": 0
     },
@@ -8408,7 +8408,7 @@
     },
     "_lpos": {
       "__type__": "cc.Vec3",
-      "x": 85,
+      "x": 140,
       "y": 0,
       "z": 0
     },
@@ -8744,11 +8744,11 @@
       "height": 40
     },
     "_startAxis": 0,
-    "_paddingLeft": 5,
+    "_paddingLeft": 10,
     "_paddingRight": 0,
     "_paddingTop": 0,
     "_paddingBottom": 0,
-    "_spacingX": 0,
+    "_spacingX": 10,
     "_spacingY": 0,
     "_verticalDirection": 1,
     "_horizontalDirection": 0,
@@ -23937,6 +23937,7 @@
     "refresh_stone_num_node": {
       "__id__": 209
     },
+    "ebars_node": null,
     "_id": ""
   },
   {
@@ -24018,6 +24019,9 @@
       "__uuid__": "66d7902d-2a85-43d5-8cbb-671cc7dbb275",
       "__expectedType__": "cc.Prefab"
     },
+    "ebars_node": {
+      "__id__": 421
+    },
     "_id": ""
   },
   {