feat(event): 在事件描述中添加变量支持

事件对话框现在会格式化描述文本，将 `{变量名}` 这样的占位符替换为来自 `EventContext` 的当前值。

这允许事件文本能够动态变化，以反映游戏状态或事件中的选择。添加了 `Wula_Test_VariableEvent` 测试事件来演示和验证此功能。

1.6/Defs/EventDefs/EventDef_VariableTest.xml

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<Defs>
+
+  <WulaFallenEmpire.EventDef>
+    <defName>Wula_Test_VariableEvent</defName>
+    <label>变量测试事件</label>
+    <characterName>测试员</characterName>
+    <portraitPath>Textures/Wula/Events/Portraits/Wula_Leader</portraitPath>
+    
+    <immediateEffects>
+      <li>
+        <effects>
+          <li Class="WulaFallenEmpire.Effect_SetVariable">
+            <name>testNumber</name>
+            <value>100</value>
+          </li>
+        </effects>
+      </li>
+    </immediateEffects>
+
+    <descriptions>
+      <li>变量 testNumber 的当前值为 {testNumber}。点击下面的按钮来改变它。</li>
+    </descriptions>
+
+    <options>
+      <li>
+        <label>将 testNumber 增加50并重新打开</label>
+        <optionEffects>
+          <li>
+            <effects>
+              <li Class="WulaFallenEmpire.Effect_ModifyVariable">
+                <name>testNumber</name>
+                <operation>Add</operation>
+                <value>50</value>
+              </li>
+              <li Class="WulaFallenEmpire.Effect_CloseDialog" />
+              <li Class="WulaFallenEmpire.Effect_OpenCustomUI">
+                <defName>Wula_Test_VariableEvent</defName>
+              </li>
+            </effects>
+          </li>
+        </optionEffects>
+      </li>
+      <li>
+        <label>关闭</label>
+        <optionEffects>
+          <li>
+            <effects>
+              <li Class="WulaFallenEmpire.Effect_CloseDialog" />
+            </effects>
+          </li>
+        </optionEffects>
+      </li>
+    </options>
+  </WulaFallenEmpire.EventDef>
+
+</Defs>

Source/WulaFallenEmpire/EventSystem/Dialog_CustomDisplay.cs

@@ -84,6 +84,9 @@ namespace WulaFallenEmpire
             }
             
             HandleAction(def.immediateEffects);
+            
+            // Format the description AFTER immediate effects have run
+            selectedDescription = FormatDescription(selectedDescription);
         }
 
         public override void DoWindowContents(Rect inRect)
@@ -256,5 +259,14 @@ namespace WulaFallenEmpire
             base.PostClose();
             HandleAction(def.dismissEffects);
         }
+       private string FormatDescription(string description)
+       {
+           var variables = EventContext.GetAllVariables();
+           foreach (var variable in variables)
+           {
+               description = description.Replace("{" + variable.Key + "}", variable.Value.ToString());
+           }
+           return description;
+       }
     }
 }

Source/WulaFallenEmpire/EventSystem/EventContext.cs

@@ -48,6 +48,11 @@ namespace WulaFallenEmpire
             return variables.ContainsKey(name);
         }
 
+        public static Dictionary<string, object> GetAllVariables()
+        {
+            return new Dictionary<string, object>(variables);
+        }
+
         public static void Clear()
         {
             variables.Clear();