refactor(employeeProfile): 优化职业资格证书展示逻辑

调整证书数据的渲染方式，改用label作为循环key避免潜在问题，新增无数据提示，同时重构计算逻辑直接从qualificationData获取时间数据

src/views/portraitManagement/employeeProfile/index.vue

@@ -135,9 +135,10 @@
           </Card>
           <Card title="职业资格证书获取时间">
             <div class="cert-info">
-              <div class="cert-item" v-for="level in displayQualificationLevels" :key="level.field">
-                <span class="cert-name">{{ level.label }}：{{ qualificationData?.[level.field] || '-' }}</span>
+              <div class="cert-item" v-for="level in displayQualificationLevels" :key="level.label">
+                <span class="cert-name">{{ level.label }}：{{ level.time }}</span>
               </div>
+              <span v-if="displayQualificationLevels.length === 0" class="no-data">暂无证书数据</span>
             </div>
           </Card>
         </div>
@@ -312,11 +313,11 @@ const qualificationLevelMap = [
 ]
 
 const displayQualificationLevels = computed(() => {
-  const currentLevel = portrait.value?.qualificationLevelText
-  if (!currentLevel) return []
-  const currentIndex = qualificationLevelMap.findIndex(l => l.label === currentLevel)
-  if (currentIndex === -1) return []
-  return qualificationLevelMap.slice(currentIndex)
+  if (!qualificationData.value) return []
+  return qualificationLevelMap.map(item => ({
+    label: item.label,
+    time: qualificationData.value[item.field]
+  })).filter(item => item.time)
 })