fix: 修复工作流入口标题与提示词校验

- 支持系统入口标题清空占位与下游引用展示同步

- 降低字段编辑触发的节点图重算和无效渲染

- 在保存及执行前拦截空白的大模型用户提示词

easyflow-ui-admin/packages/tinyflow-ui/src/components/core/DefinedParameterItem.svelte

@@ -52,9 +52,10 @@
         return param.formType ? [param.formType] : [];
     });
     let parameterNameDraft = $state<string | null>(null);
+    let systemLabelDraft = $state<string | null>(null);
     let displayParamName = $derived.by(() => {
         if (isSystemStartParam) {
-            return '用户问题';
+            return systemLabelDraft ?? trimString(param.formLabel);
         }
         return parameterNameDraft ?? param.name;
     });
@@ -76,6 +77,8 @@
 
     const applyStartFieldPatch = (fieldKey: string, patch: Record<string, any>) => {
         const currentFieldId = trimString(param.id);
+        const shouldSyncReferences = Object.prototype.hasOwnProperty.call(patch, 'key')
+            || Object.prototype.hasOwnProperty.call(patch, 'label');
         store.updateNodes((nodes) => {
             const edges = store.getEdges();
             let nextFieldKey = fieldKey;
@@ -98,6 +101,9 @@
                     }
                 };
             });
+            if (!shouldSyncReferences) {
+                return nextNodes;
+            }
             return renameStartFieldReferencesInNodes(
                 nextNodes,
                 edges,
@@ -172,11 +178,11 @@
     const updateName = (event: Event) => {
         const input = event.target as HTMLInputElement;
         const newValue = input.value;
+        parameterNameDraft = newValue;
         if (isStartNodeInputParam) {
             const normalizedValue = trimString(newValue);
             if (!normalizedValue) {
                 parameterNameError = '参数名不能为空';
-                parameterNameDraft = newValue;
                 return;
             }
             if (!isStartFormFieldKeyAvailable(
@@ -185,13 +191,66 @@
                 normalizedValue
             )) {
                 parameterNameError = '参数名已存在';
-                parameterNameDraft = newValue;
                 return;
             }
         }
+        parameterNameError = '';
+    };
+
+    const updateVisibleName = (event: Event) => {
+        if (isSystemStartParam) {
+            systemLabelDraft = (event.target as HTMLInputElement).value;
+            return;
+        }
+        updateName(event);
+    };
+
+    const commitName = () => {
+        if (parameterNameDraft === null) {
+            return;
+        }
+        const draftValue = parameterNameDraft;
+        if (isStartNodeInputParam) {
+            const normalizedValue = trimString(draftValue);
+            if (!normalizedValue) {
+                parameterNameError = '参数名不能为空';
+                return;
+            }
+            if (!isStartFormFieldKeyAvailable(
+                node?.current?.data as Record<string, any>,
+                param.name || '',
+                normalizedValue
+            )) {
+                parameterNameError = '参数名已存在';
+                return;
+            }
+            parameterNameDraft = null;
+            parameterNameError = '';
+            if (normalizedValue !== trimString(param.name)) {
+                updateParameter('name', normalizedValue);
+            }
+            return;
+        }
         parameterNameDraft = null;
         parameterNameError = '';
-        updateParameter('name', newValue);
+        if (draftValue !== (param.name || '')) {
+            updateParameter('name', draftValue);
+        }
+    };
+
+    const commitVisibleName = () => {
+        if (!isSystemStartParam) {
+            commitName();
+            return;
+        }
+        if (systemLabelDraft === null) {
+            return;
+        }
+        const nextLabel = trimString(systemLabelDraft);
+        systemLabelDraft = null;
+        if (nextLabel !== trimString(param.formLabel)) {
+            updateParameter('formLabel', nextLabel);
+        }
     };
 
     const updateRequired = (event: Event) => {
@@ -236,11 +295,13 @@
 
 
 <div class="input-item input-item-name">
-    <Input style="width: 100%;" value={displayParamName} placeholder="请输入参数名称"
-           disabled={param.nameDisabled === true}
+    <Input style="width: 100%;" value={displayParamName}
+           placeholder={isSystemStartParam ? '用户问题' : '请输入参数名称'}
+           disabled={isSystemStartParam ? false : param.nameDisabled === true}
            aria-invalid={parameterNameError ? 'true' : undefined}
            aria-describedby={parameterNameError ? parameterNameErrorId : undefined}
-           oninput={updateName} />
+           oninput={updateVisibleName}
+           onchange={commitVisibleName} />
     {#if parameterNameError}
         <div id={parameterNameErrorId} class="input-error" role="alert">
             {parameterNameError}
@@ -296,7 +357,7 @@
                     数据标题：
                     <Textarea rows={1} style="width: 100%;" onchange={(event)=>{
                         updateParamByEvent('formLabel', event)
-                    }} value={param.formLabel} />
+                    }} value={param.formLabel} placeholder={isSystemStartParam ? '用户问题' : undefined} />
                 </div>
 
                 <div class="input-more-item">