feat(tts): 添加语音剪气口功能以去除首尾静音

- 集成 ffmpeg 实现自动检测并切除音频首尾静音段
- 新增 trimSilence 和 getAudioDuration 辅助函数
- 裁剪后若时长缩短则替换原音频文件，使片段时长更贴近真实语长
- 更新剪映草稿路径和 capcut-mate 目录配置

.claude/skills/config.json

@@ -1,6 +1,6 @@
 {
-  "jianyingDraftPath": "/Users/lc/Movies/JianyingPro/User Data/Projects/com.lveditor.draft",
+  "jianyingDraftPath": "C:/Users/45070/AppData/Local/JianyingPro/User Data/Projects/com.lveditor.draft",
-  "capcutMateDir": "C:/Users/45070/capcut-mate",
+  "capcutMateDir": "/Users/lc/capcut-mate",
   "capcutMateApiBase": "http://capcut.muyetools.cn/openapi/capcut-mate/v1",
   "imgbbApiKey": "deprecated",
   "geminiApiBaseUrl": "https://yunwu.ai",

.claude/skills/video-from-script/scripts/sync-to-jianying.js

@@ -155,6 +155,9 @@ function registerDraft(draftId, draftName, totalDurationUs) {
   const rootMetaPath = path.join(jianyingDraftPath, 'root_meta_info.json')
   const draftDir = path.join(jianyingDraftPath, draftId)
 
+  if (!fs.existsSync(rootMetaPath)) {
+    fs.writeFileSync(rootMetaPath, JSON.stringify({ all_draft_store: [] }, null, 4), 'utf-8')
+  }
   const rootMeta = JSON.parse(fs.readFileSync(rootMetaPath, 'utf-8'))
   if (rootMeta.all_draft_store.some(d => d.draft_fold_path === winPath(draftDir))) {
     console.log('  已注册，跳过')