更新返回按钮逻辑，添加从场景页面跳转的状态管理

modeler/src/views/decision/designer/designer.vue

@@ -29,7 +29,7 @@
                   <span>保存</span>
                 </a-button>
 
-                <a-button v-if="currentScenarioId" class="ks-model-builder-save" size="small" @click="handleGoback">
+                <a-button v-if="fromScenarioPage" class="ks-model-builder-save" size="small" @click="handleGoback">
                   <BackwardFilled />
                   <span>返回</span>
                 </a-button>
@@ -125,6 +125,7 @@ export default defineComponent({
     const nodeCommands = ref<NodeCommand[]>([])
     const currentScenarioId = ref<number | undefined>();
     const currentPlatformId = ref<number | null>(null);
+    const fromScenarioPage = ref<boolean>(false);
 
     const {
       handleGraphEvent,
@@ -270,7 +271,6 @@ export default defineComponent({
     const handleSelectTree = (tree: BehaviorTree) => {
       destroyGraph();
       currentPlatformId.value = null; 
-      // currentScenarioId.value = undefined;
 
       console.info('handleSelectTree', tree);
       findOneTreeById(tree.id).then(r => {
@@ -334,14 +334,27 @@ export default defineComponent({
       });
     };
 
+    const STORAGE_KEY_SCENARIO = 'designer_from_scenario_id';
+
     const resolveQuery = ()=> {
       console.log(currentRoute);
       
       let scenarioId = Number(currentRoute.query.scenario);
-      if (!isNaN(scenarioId)) {
+      if (!isNaN(scenarioId) && scenarioId > 0) {
         currentScenarioId.value = scenarioId;
+        fromScenarioPage.value = true;
+        sessionStorage.setItem(STORAGE_KEY_SCENARIO, String(scenarioId));
+      } else {
+        // 尝试从 sessionStorage 恢复（页面刷新或 SPA 内部跳转后 query 参数丢失的情况）
+        const stored = sessionStorage.getItem(STORAGE_KEY_SCENARIO);
+        const storedId = Number(stored);
+        if (stored && !isNaN(storedId) && storedId > 0) {
+          currentScenarioId.value = storedId;
+          fromScenarioPage.value = true;
         } else {
           currentScenarioId.value = undefined;
+          fromScenarioPage.value = false;
+        }
       }
       let platformId = Number(currentRoute.query.platform);
       if (!isNaN(platformId)) {
@@ -476,6 +489,7 @@ export default defineComponent({
     };
 
     const handleGoback = ()=> {
+      sessionStorage.removeItem(STORAGE_KEY_SCENARIO);
       window.location.href = `/app/decision/communication?scenario=${currentScenarioId.value}`
     }
 
@@ -555,6 +569,7 @@ export default defineComponent({
       handleUpdateElement,
       handleSelectTree,
       handleGoback,
+      fromScenarioPage,
     };
   },
 });