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",
-  "capcutMateDir": "C:/Users/45070/capcut-mate",
+  "jianyingDraftPath": "C:/Users/45070/AppData/Local/JianyingPro/User Data/Projects/com.lveditor.draft",
+  "capcutMateDir": "/Users/lc/capcut-mate",
   "capcutMateApiBase": "http://capcut.muyetools.cn/openapi/capcut-mate/v1",
   "imgbbApiKey": "deprecated",
   "geminiApiBaseUrl": "https://yunwu.ai",
@@ -34,4 +34,4 @@
   "ttsModel": "cosyvoice-v3.5-plus",
   "ttsVoice": "cosyvoice-v3.5-plus-bailian-fa8787c0f70b4ba2a907c35511e6a6f6",
   "ttsLanguage": "Chinese"
-}
+}