为随机角色卡补 hover 反向链路

新增 SelectRoleClearEventArgs：hover 随机卡时清空选中状态，让上方属性区回到 _randomRoleCard。

- SelectRoleForm.OnRandomHoverEnter 上报事件
- SelectRoleUseCase.ClearSelection 重置 SelectedRoleId 并重建 RawData
- SelectRoleController 订阅事件并刷新 Context
- SelectRoleForm.prefab 随机卡 _onPointerEnterAction 绑定新方法

Assets/GameMain/Scripts/Base/Event/SelectRoleForm/SelectRoleClearEventArgs.cs

@@ -0,0 +1,21 @@
+using GameFramework;
+using GameFramework.Event;
+
+namespace SepCore.Event
+{
+    public class SelectRoleClearEventArgs : GameEventArgs
+    {
+        public static readonly int EventId = typeof(SelectRoleClearEventArgs).GetHashCode();
+
+        public override int Id => EventId;
+
+        public static SelectRoleClearEventArgs Create()
+        {
+            return ReferencePool.Acquire<SelectRoleClearEventArgs>();
+        }
+
+        public override void Clear()
+        {
+        }
+    }
+}