add method extract_story_title

tool_core.js

@@ -329,13 +329,26 @@ module.exports = {
 
   // 返回新的数组
   filter_story (story) {
-    if (Array.isArray(story)) {
+    if (Array.isArray(story) && story.length) {
       return story.filter((section) => Object.values(section || {}).some((val) => !this.is_empty(val))) // (section.text || section.image || section.video)?.trim?.()
     } else {
       return []
     }
   },
 
+  extract_story_title (story) {
+    if (Array.isArray(story) && story.length) {
+      return (
+        story
+          .map(({ text = '' } = {}) => text.trim().replace(/\n/g, ' '))
+          .join(' ')
+          .substring(0, 140) || ''
+      )
+    } else {
+      return ''
+    }
+  },
+
   is_empty (data) {
     // empty: undefined, null, false, 0, NaN, '', '空格，tab, \n等', [], {}
     if (data) {