添加“奖励 3 选 1”UI

- RewardSelectForm：其中包括 3 个可选的 RewardItem ，刷新和放弃按钮
- 应用战斗节点基地生命产生的额外事件

Assets/GameMain/Scripts/UI/Game/Controller/RepoFormController.cs

@@ -93,7 +93,8 @@ namespace GeometryTD.UI
                     {
                         Title = $"[Tower] {tower.Name}  ({tower.Rarity})",
                         InstanceId = tower.InstanceId,
-                        ComponentSlotType = TowerCompSlotType.None
+                        ComponentSlotType = TowerCompSlotType.None,
+                        IconAreaContext = BuildIconAreaContext(tower.Rarity)
                     });
                 }
             }
@@ -106,7 +107,8 @@ namespace GeometryTD.UI
                     {
                         Title = $"[Muzzle] {item.Name}  ({item.Rarity})",
                         InstanceId = item.InstanceId,
-                        ComponentSlotType = TowerCompSlotType.Muzzle
+                        ComponentSlotType = TowerCompSlotType.Muzzle,
+                        IconAreaContext = BuildIconAreaContext(item.Rarity)
                     });
                 }
             }
@@ -119,7 +121,8 @@ namespace GeometryTD.UI
                     {
                         Title = $"[Bearing] {item.Name}  ({item.Rarity})",
                         InstanceId = item.InstanceId,
-                        ComponentSlotType = TowerCompSlotType.Bearing
+                        ComponentSlotType = TowerCompSlotType.Bearing,
+                        IconAreaContext = BuildIconAreaContext(item.Rarity)
                     });
                 }
             }
@@ -132,7 +135,8 @@ namespace GeometryTD.UI
                     {
                         Title = $"[Base] {item.Name}  ({item.Rarity})",
                         InstanceId = item.InstanceId,
-                        ComponentSlotType = TowerCompSlotType.Base
+                        ComponentSlotType = TowerCompSlotType.Base,
+                        IconAreaContext = BuildIconAreaContext(item.Rarity)
                     });
                 }
             }
@@ -158,6 +162,15 @@ namespace GeometryTD.UI
             _itemContextMap[itemContext.InstanceId] = itemContext;
         }
 
+        private static IconAreaContext BuildIconAreaContext(RarityType rarity)
+        {
+            return new IconAreaContext
+            {
+                Rarity = rarity,
+                Icon = null
+            };
+        }
+
         private void OnRepoItemSelected(object sender, GameEventArgs e)
         {
             if (!(e is RepoItemSelectedEventArgs args))