feat(sync): 长语音音频本地化(voice_clip media_hash+download+local-first playback)

Mirror download_call_recordings pattern for voice_clips:
- VoiceClip.media_hash column + Alembic migration (c4d5e6f7a8b9)
- VoiceClipOut.media_hash + frontend VoiceClip.media_hash type
- download_voice_clip_audio in app/scraper/media.py (resilient, sha256-dedup,
  same download_url/upsert_media helpers as call recordings)
- sync_voice_clip_audio orchestrator wrapper (commits own SyncRun, mirrors
  sync_call_recordings semantics)
- scheduler: _run_voice_clip_audio + ENTITY_FUNCS['voice_clip_audio'] +
  appended to daily _run_all job (after voice_clips)
- VoiceClipModal playClip local-first: /api/media/{media_hash} with OSS
  oss_file_name fallback (mirrors CallList.playRecord)

Tested: 376 pytest pass; vue-tsc clean; migration applied; 1523/1533 clips
localized (10 pending are genuine upstream HTTP 404s — resilient skip).

Co-Authored-By: Claude <noreply@anthropic.com>

yunkes/src/components/VoiceClipModal.vue

@@ -15,7 +15,8 @@ import { formatCallDuration, formatTime } from '@/utils/format'
  * 关联到 customer.friend_id，不回写云客。matched_friend_name 由后端在 GET 时
  * 经 Customer join 解析（remark > nickname > real_name > friend_id）。
  *
- * 录音播放仍用 `oss_file_name` 的 OSS 直链（已知全本地妥协，随 ASR 一起修）。
+ * 录音播放采用 local-first：优先 `/api/media/{media_hash}`（本地化音频），
+ * 回退到 `oss_file_name` 的 OSS 直链（mirrors CallList.playRecord）。
  */
 const props = withDefaults(
   defineProps<{
@@ -146,7 +147,10 @@ const displayItems = computed(() =>
 )
 
 function playClip(row: VoiceClip): void {
-  const url = row.oss_file_name
+  // Local-first: 优先本地化的 /api/media/{media_hash}，回退到 OSS 直链
+  // (mirrors CallList.playRecord)。
+  const local = row.media_hash ? `/api/media/${row.media_hash}` : null
+  const url = local ?? row.oss_file_name
   if (!url) {
     ElMessage.info('该片段无录音文件')
     return