fix(douyin): 支持分享文本自动提取URL + MediaKit ASR 云端转写

P1 修复：
1. 抖音链接提取：后端自动从分享文本（如"这个视频 https://v.douyin.com/xxx/ 快来看看"）
   中正则提取 http(s) URL，不再要求用户只粘贴纯链接；
   裸域名（v.douyin.com/xxx）自动补 https://；ftp/file 等非 http(s) 协议拒绝。
2. 抖音文案提取换方案：优先走火山引擎 MediaKit asr-subtitles API（云端 ASR），
   利用 yt-dlp 解析无水印直链（不下载整段视频）→ 提交 MediaKit → 轮询拿字幕；
   MediaKit 未配置/失败时回退到原"下载视频+本地 ASR"路径；cookies 503 友好错误保留。
3. 文案库 P1-1 排查结论：后端 GET /api/v1/scripts CRUD 正常，scripts 表结构/数据
   在 070/077/078 迁移链路中无数据丢失；"数据不显示"应是前端未正确切换到新接口，
   已在回复中说明。

测试：新增 13 个 URL 提取单测；原有 15576 单测全绿；ruff clean.

apps/api/app/api/routes/scripts_ai.py

@@ -1,7 +1,12 @@
-"""Scripts AI 能力路由 — Issue #1893.
+"""Scripts AI 能力路由 — Issue #1893/#1963.
 
 三个 AI 工具接口（均挂载在 /api/v1/scripts 前缀下）：
-- POST /extract-from-douyin  从抖音视频提取文案（yt-dlp 下载 + ASR 转写）
+- POST /extract-from-douyin  从抖音视频提取文案
+  - 入口自动从分享文本中正则提取 http(s) URL，兼容 "复制链接" 粘贴场景
+  - yt-dlp 仅解析视频元信息（download=False）拿无水印直链，避免整段下载
+  - 优先走火山 MediaKit ASR（asr-subtitles），配置了 MEDIAKIT_API_KEY 即可用
+  - MediaKit 不可用/失败时，回退到本地 ASR（下载视频 + transcribe_to_text）
+  - cookies/ytdlp 均失败时，返回友好 503 不暴露内部错误
 - POST /ai-rewrite           AI 文案改写（复用豆包 LLM）
 - POST /ai-generate-titles   AI 标题生成（复用 generate_smart_titles）
 """
@@ -12,6 +17,8 @@ import logging
 import os
 import re
 import tempfile
+import time
+from urllib.parse import urlparse
 
 from app.auth import AuthenticatedUser, get_current_user
 from app.dependencies import get_db_session
@@ -23,6 +30,11 @@ from app.schemas.scripts_ai import (
     ExtractFromDouyinRequest,
     ExtractFromDouyinResponse,
 )
+from app.services.mediakit_client import (
+    MediaKitClient,
+    MediaKitError,
+    get_mediakit_client,
+)
 from app.services.script_asr_service import (
     ASRNotConfiguredError,
     ASRTranscriptionError,
@@ -38,16 +50,12 @@ logger = logging.getLogger(__name__)
 
 router = APIRouter()
 
-# 抖音 cookies 文件路径（Netscape 格式），由环境变量 DOUYIN_COOKIES_FILE 覆盖
-# 默认路径与 deploy/configs/douyin_cookies.txt 对应（容器内挂载到 /app/configs/）
 DOUYIN_COOKIES_FILE = os.environ.get(
     "DOUYIN_COOKIES_FILE",
     "/app/configs/douyin_cookies.txt",
 )
-# baked-in 兜底 cookies 路径（镜像构建时 COPY，host 挂载为空文件时 fallback）
 DOUYIN_COOKIES_FILE_BAKED = "/app/configs/douyin_cookies_default.txt"
 
-# cookies 失效/需要刷新的错误关键词
 _COOKIES_ERROR_KEYWORDS = (
     "fresh cookies",
     "cookies (not necessarily logged in)",
@@ -61,9 +69,10 @@ _COOKIES_ERROR_KEYWORDS = (
     "cookies过期",
 )
 
+_TAIL_PUNCT = ".,;:!?，。；：！？)）]》" + chr(34) + chr(39) + "<>"
 
-def _resolve_cookies_file() -> str | None:
-    """返回有效的 cookies 文件路径：host 挂载优先 > baked-in 兜底 > None."""
+
+def _resolve_cookies_file():
     for p in (DOUYIN_COOKIES_FILE, DOUYIN_COOKIES_FILE_BAKED):
         try:
             if p and os.path.isfile(p) and os.path.getsize(p) > 200:
@@ -73,339 +82,461 @@ def _resolve_cookies_file() -> str | None:
     return None
 
 
-def _cookies_file_exists() -> bool:
-    return _resolve_cookies_file() is not None
-
-
-def _dbg(key: str, val: str) -> None:
-    """记录抖音调试信息（debug 日志）。"""
+def _dbg(key, val):
     logger.debug("douyin_extract %s=%s", key, str(val)[:200])
 
 
-def _is_cookies_related_error(msg: str) -> bool:
-    """判断 yt-dlp 的错误是否与 cookies 缺失/过期有关."""
+def _is_cookies_related_error(msg):
     low = msg.lower()
     return any(kw in low for kw in _COOKIES_ERROR_KEYWORDS)
 
 
-# 启动时记录 cookies 状态，便于排查
 _cf = _resolve_cookies_file()
 if _cf:
     logger.info("抖音 cookies 文件已加载: %s (%d bytes)", _cf, os.path.getsize(_cf))
 else:
     logger.warning(
-        "抖音 cookies 文件未找到或无效: path=%s baked=%s 抖音提取功能可能因 cookies 缺失失败",
+        "抖音 cookies 文件未找到或无效: path=%s baked=%s",
         DOUYIN_COOKIES_FILE,
         DOUYIN_COOKIES_FILE_BAKED,
     )
 
-# 是否在错误响应中暴露原始 yt-dlp 错误（仅 staging/dev 用于排查，生产默认 False）
 _DOUYIN_DEBUG_ERRORS = os.environ.get("DOUYIN_DEBUG_ERRORS", "").lower() in ("1", "true", "yes")
 
-# 抖音 URL 校验：支持短链 v.douyin.com 和长链 www.douyin.com/video/
-_DOUYIN_URL_RE = re.compile(
-    r"^(https?://)?(v\.douyin\.com/\S+|www\.douyin\.com/video/\S+)$",
+_URL_EXTRACT_RE = re.compile(r"https?://\S+", re.IGNORECASE)
+_DOUYIN_HOST_RE = re.compile(
+    r"(^|\.)(douyin\.com|iesdouyin\.com|amemv\.com)$",
     re.IGNORECASE,
 )
+_ANY_SCHEME_RE = re.compile(r"^[a-z][a-z0-9+.-]*://\S+", re.IGNORECASE)
 
 
-def _validate_douyin_url(url: str) -> None:
-    """校验抖音 URL 格式，不合法时抛 HTTPException(400)."""
-    if not url or not url.strip():
+def _extract_url_from_text(raw):
+    if not raw:
+        return None
+    m = _URL_EXTRACT_RE.search(raw)
+    if m:
+        return m.group(0).rstrip(_TAIL_PUNCT)
+    short = re.search(
+        r"(?:^|(?<![a-z0-9/:]))((?:v|www)\.douyin\.com/\S+|douyin\.com/(?:video|note)/\S+)",
+        raw,
+        re.IGNORECASE,
+    )
+    if short:
+        return "https://" + short.group(1).rstrip(_TAIL_PUNCT)
+    return None
+
+
+def _extract_and_validate_douyin_url(raw_input):
+    raw = (raw_input or "").strip()
+    if not raw:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="链接不能为空")
+
+    url = _extract_url_from_text(raw)
+
+    if not url:
+        # 含非 http(s) 的 scheme 前缀（如 ftp://、file:// 等）→ 协议不支持
+        if _ANY_SCHEME_RE.search(raw):
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="无效的抖音链接，仅支持 http(s) 协议",
+            )
+        # 裸域名兜底：在去除 scheme 的情况下匹配 douyin 域名
+        short = re.search(
+            r"(?:^|(?<![a-z0-9]))((?:v|www)\.douyin\.com/\S+|douyin\.com/(?:video|note)/\S+)",
+            raw,
+            re.IGNORECASE,
+        )
+        if short:
+            url = "https://" + short.group(1).rstrip(_TAIL_PUNCT)
+        else:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="未在输入中找到有效抖音链接，请粘贴包含 v.douyin.com 或 www.douyin.com 的分享文本",
+            )
+
+    if not re.match(r"^https?://", url, re.IGNORECASE):
+        url = "https://" + url
+
+    try:
+        parsed = urlparse(url)
+        host = parsed.hostname or ""
+        scheme = (parsed.scheme or "").lower()
+    except Exception:
+        host = ""
+        scheme = ""
+    if scheme not in ("http", "https"):
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
-            detail="链接不能为空",
+            detail="无效的抖音链接，仅支持 http(s) 协议",
         )
-    if not _DOUYIN_URL_RE.match(url.strip()):
+    if not _DOUYIN_HOST_RE.search(host):
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
-            detail="无效的抖音链接，仅支持 v.douyin.com 短链或 www.douyin.com/video/ 长链",
+            detail="无效的抖音链接，仅支持 douyin.com 域名（v.douyin.com 短链或 www.douyin.com 长链）",
         )
+    return url
 
 
-# ── 1. 从抖音视频提取文案 ─────────────────────────────────────────────────────
+# ── MediaKitClient ASR 扩展（monkey patch） ────────────────────────────
 
 
-@router.post(
-    "/extract-from-douyin",
-    response_model=ExtractFromDouyinResponse,
-)
+def _mk_post_json(self, path, payload):
+    import httpx
+    if not self.is_available:
+        raise MediaKitError("MediaKit API Key 未配置", code="NotConfigured")
+    url = self._base_url + path
+    try:
+        with httpx.Client(timeout=self._timeout) as http:
+            resp = http.post(url, headers=self._headers(), json=payload)
+            resp.raise_for_status()
+            data = resp.json()
+    except httpx.TimeoutException as exc:
+        raise MediaKitError("MediaKit API 超时 (%ss)" % self._timeout, code="Timeout") from exc
+    except httpx.HTTPStatusError as exc:
+        raise MediaKitError(
+            "MediaKit API HTTP %s: %s" % (exc.response.status_code, exc.response.text[:300]),
+            code="HttpError",
+        ) from exc
+    except httpx.RequestError as exc:
+        raise MediaKitError("MediaKit API 网络错误: %s" % exc, code="NetworkError") from exc
+    if not data.get("success", True) and data.get("error"):
+        err = data["error"]
+        raise MediaKitError(err.get("message", "请求失败"), code=err.get("code", "RequestFailed"))
+    return data
+
+
+def _mk_get_json(self, path):
+    import httpx
+    if not self.is_available:
+        raise MediaKitError("MediaKit API Key 未配置", code="NotConfigured")
+    url = self._base_url + path
+    try:
+        with httpx.Client(timeout=self._timeout) as http:
+            resp = http.get(url, headers=self._headers())
+            resp.raise_for_status()
+            return resp.json()
+    except httpx.TimeoutException as exc:
+        raise MediaKitError("MediaKit API 超时 (%ss)" % self._timeout, code="Timeout") from exc
+    except httpx.HTTPStatusError as exc:
+        raise MediaKitError(
+            "MediaKit API HTTP %s: %s" % (exc.response.status_code, exc.response.text[:300]),
+            code="HttpError",
+        ) from exc
+    except httpx.RequestError as exc:
+        raise MediaKitError("MediaKit API 网络错误: %s" % exc, code="NetworkError") from exc
+
+
+def _mediakit_asr_submit(self, video_url):
+    data = self._post_json(
+        "/tools/asr-subtitles",
+        {"video_url": video_url, "language": "cmn-Hans-CN"},
+    )
+    task_id = data.get("task_id")
+    if not task_id:
+        raise MediaKitError("MediaKit ASR 提交响应缺少 task_id")
+    return task_id
+
+
+def _mediakit_asr_poll(self, task_id, poll_interval=2.0, max_attempts=90):
+    for _ in range(max_attempts):
+        time.sleep(poll_interval)
+        data = self._get_json("/tasks/" + task_id)
+        st = data.get("status")
+        if st in ("completed", "success"):
+            result = data.get("result") or {}
+            subs = result.get("subtitles") or []
+            text = "".join(s.get("subtitle_text", "") for s in subs if isinstance(s, dict))
+            duration = float(result.get("duration") or 0.0)
+            return text.strip(), duration
+        if st == "failed":
+            err = data.get("error") or {}
+            raise MediaKitError(
+                "MediaKit ASR 任务失败: %s" % err.get("message", "unknown"),
+                code=err.get("code", "TaskFailed"),
+            )
+    raise MediaKitError(
+        "MediaKit ASR 超时（%ss 未完成）" % int(poll_interval * max_attempts),
+        code="Timeout",
+    )
+
+
+if not hasattr(MediaKitClient, "_post_json"):
+    MediaKitClient._post_json = _mk_post_json
+if not hasattr(MediaKitClient, "_get_json"):
+    MediaKitClient._get_json = _mk_get_json
+if not hasattr(MediaKitClient, "asr_submit"):
+    MediaKitClient.asr_submit = _mediakit_asr_submit
+if not hasattr(MediaKitClient, "asr_poll"):
+    MediaKitClient.asr_poll = _mediakit_asr_poll
+
+
+# ── yt-dlp 辅助 ──────────────────────────────────────────────────────
+
+
+def _ytdlp_extract_video_url(page_url, cookiefile=None):
+    try:
+        import yt_dlp
+    except ImportError:
+        logger.warning("yt-dlp 未安装，无法解析抖音直链")
+        return None, 0.0
+    opts = {
+        "quiet": True,
+        "no_warnings": True,
+        "noplaylist": True,
+        "skip_download": True,
+        "http_headers": {
+            "User-Agent": (
+                "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
+                "AppleWebKit/537.36 (KHTML, like Gecko) "
+                "Chrome/128.0.0.0 Safari/537.36"
+            ),
+            "Referer": "https://www.douyin.com/",
+        },
+    }
+    if cookiefile:
+        opts["cookiefile"] = cookiefile
+    try:
+        with yt_dlp.YoutubeDL(opts) as ydl:
+            info = ydl.extract_info(page_url, download=False)
+    except Exception as exc:
+        _dbg("ytdlp_err", str(exc)[:300])
+        logger.info("yt-dlp 解析抖音直链失败（将降级）: %s", str(exc)[:200])
+        return None, 0.0
+    if not info:
+        return None, 0.0
+    video_url = info.get("url")
+    if not video_url:
+        for f in (info.get("requested_formats") or info.get("formats") or []):
+            if f.get("url"):
+                video_url = f["url"]
+                break
+    try:
+        duration = float(info.get("duration") or 0)
+    except (TypeError, ValueError):
+        duration = 0.0
+    return video_url, duration
+
+
+def _ytdlp_download_and_local_asr(page_url, temp_dir, cookiefile=None):
+    try:
+        import yt_dlp
+    except ImportError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="抖音提取功能暂不可用（缺少依赖 yt-dlp）",
+        ) from exc
+    opts = {
+        "format": "best[ext=mp4]/best",
+        "outtmpl": temp_dir + "/%(id)s.%(ext)s",
+        "quiet": True,
+        "no_warnings": True,
+        "noplaylist": True,
+        "http_headers": {
+            "User-Agent": (
+                "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
+                "AppleWebKit/537.36 (KHTML, like Gecko) "
+                "Chrome/128.0.0.0 Safari/537.36"
+            ),
+            "Referer": "https://www.douyin.com/",
+        },
+    }
+    if cookiefile:
+        opts["cookiefile"] = cookiefile
+
+    info = None
+    try:
+        with yt_dlp.YoutubeDL(opts) as ydl:
+            info = ydl.extract_info(page_url, download=True)
+    except yt_dlp.utils.DownloadError as exc:
+        msg = str(exc)
+        logger.warning("抖音下载失败: url=%s error=%s", page_url, msg)
+        if _is_cookies_related_error(msg):
+            _detail = "抖音链接解析暂时不可用，请稍后重试或手动输入文案"
+            if _DOUYIN_DEBUG_ERRORS:
+                _detail = _detail + " [debug: " + msg[:300] + "]"
+            raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail=_detail) from exc
+        is_bad_url = any(
+            kw in msg.lower()
+            for kw in (
+                "404", "not found", "unable to download webpage",
+                "unsupported url", "no video formats", "video unavailable",
+                "this video isn't available",
+            )
+        )
+        _detail = "无法解析该抖音链接，请确认链接有效且视频未被下架" if is_bad_url else "视频下载失败，请稍后重试"
+        if _DOUYIN_DEBUG_ERRORS:
+            _detail = _detail + " [debug: " + msg[:300] + "]"
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST if is_bad_url else status.HTTP_502_BAD_GATEWAY,
+            detail=_detail,
+        ) from exc
+    except Exception as exc:
+        msg = str(exc)
+        logger.exception("抖音视频下载异常: url=%s error=%s", page_url, msg)
+        if _is_cookies_related_error(msg):
+            _detail = "抖音链接解析暂时不可用，请稍后重试或手动输入文案"
+            if _DOUYIN_DEBUG_ERRORS:
+                _detail = _detail + " [debug: " + msg[:300] + "]"
+            raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail=_detail) from exc
+        _detail = "视频下载失败，请稍后重试"
+        if _DOUYIN_DEBUG_ERRORS:
+            _detail = _detail + " [debug: " + msg[:300] + "]"
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail=_detail) from exc
+
+    if info is None:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="无法解析该抖音链接")
+    duration = 0.0
+    video_path = ""
+    try:
+        with yt_dlp.YoutubeDL(opts) as ydl:
+            video_path = ydl.prepare_filename(info)
+        try:
+            duration = float(info.get("duration") or 0)
+        except (TypeError, ValueError):
+            duration = 0.0
+        if not os.path.isfile(video_path) or os.path.getsize(video_path) == 0:
+            raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail="视频下载异常：未获取到有效文件")
+    except HTTPException:
+        raise
+    except Exception as exc:
+        msg = str(exc)
+        logger.exception("抖音视频后处理异常: url=%s error=%s", page_url, msg)
+        if _is_cookies_related_error(msg):
+            _detail = "抖音链接解析暂时不可用，请稍后重试或手动输入文案"
+            if _DOUYIN_DEBUG_ERRORS:
+                _detail = _detail + " [debug: " + msg[:300] + "]"
+            raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail=_detail) from exc
+        _detail = "视频处理失败，请稍后重试"
+        if _DOUYIN_DEBUG_ERRORS:
+            _detail = _detail + " [debug: " + msg[:300] + "]"
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail=_detail) from exc
+
+    try:
+        text = transcribe_to_text(video_path)
+    except ASRNotConfiguredError as exc:
+        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail=str(exc)) from exc
+    except ASRTranscriptionError as exc:
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail=str(exc)) from exc
+    except Exception as exc:
+        logger.exception("ASR 转写异常: path=%s", video_path)
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            detail="语音识别失败: " + str(exc)[:200],
+        ) from exc
+    return text.strip(), duration
+
+
+# ── 1. 从抖音视频提取文案 ─────────────────────────────────────────────
+
+
+@router.post("/extract-from-douyin", response_model=ExtractFromDouyinResponse)
 @points_gate("douyin_extract")
 def extract_from_douyin(
     request: ExtractFromDouyinRequest,
     current_user: AuthenticatedUser = Depends(get_current_user),
     db: Session = Depends(get_db_session),
-) -> ExtractFromDouyinResponse:
-    """从抖音视频下载无水印视频并通过 ASR 提取文案."""
-    source_url = request.url.strip()
-    _validate_douyin_url(source_url)
+):
+    page_url = _extract_and_validate_douyin_url(request.url)
+    _dbg("page_url", page_url)
 
-    # 确保 URL 有 scheme（yt-dlp 需要完整 URL）
-    url_for_download = source_url
-    if not re.match(r"^https?://", url_for_download, re.IGNORECASE):
-        url_for_download = "https://" + url_for_download
+    text = ""
+    duration = 0.0
+    cookiefile = _resolve_cookies_file()
+    mk_client = get_mediakit_client()
 
-    text: str = ""
-    duration: float = 0.0
+    # 路径 A：yt-dlp 拿直链 + MediaKit 云端 ASR
+    direct_url, meta_duration = _ytdlp_extract_video_url(page_url, cookiefile=cookiefile)
+    if meta_duration:
+        duration = meta_duration
+    _dbg("direct_url", direct_url or "<none>")
 
-    try:
+    if direct_url and mk_client.is_available:
+        try:
+            task_id = mk_client.asr_submit(direct_url)
+            text, mk_duration = mk_client.asr_poll(task_id)
+            if mk_duration:
+                duration = mk_duration
+            logger.info(
+                "抖音 MediaKit ASR 成功: url=%s text_len=%d duration=%.1f",
+                page_url, len(text), duration,
+            )
+        except MediaKitError as exc:
+            logger.warning("MediaKit ASR 失败，回退本地 ASR: %s", exc)
+            text = ""
+
+    # 路径 B：回退下载 + 本地 ASR
+    if not text:
+        _dbg("fallback", "download+local_asr")
         with tempfile.TemporaryDirectory(prefix="douyin_extract_") as temp_dir:
-            # 延迟导入 yt-dlp，避免模块缺失时影响其他路由启动
-            try:
-                import yt_dlp
-            except ImportError as exc:
-                logger.error("yt-dlp 未安装，抖音提取功能不可用: %s", exc)
-                raise HTTPException(
-                    status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-                    detail="抖音提取功能暂不可用（缺少依赖 yt-dlp）",
-                ) from exc
-
-            ydl_opts = {
-                "format": "best[ext=mp4]/best",
-                "outtmpl": f"{temp_dir}/%(id)s.%(ext)s",
-                "quiet": True,
-                "no_warnings": True,
-                "noplaylist": True,
-                # 抖音反爬严格，必须用真实桌面浏览器 UA
-                "http_headers": {
-                    "User-Agent": (
-                        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
-                        "AppleWebKit/537.36 (KHTML, like Gecko) "
-                        "Chrome/128.0.0.0 Safari/537.36"
-                    ),
-                    "Referer": "https://www.douyin.com/",
-                },
-            }
-
-            # 如果存在抖音 cookies 文件，传给 yt-dlp 绕过反爬（host 挂载优先，空文件 fallback 到镜像内）
-            _cookies_path = _resolve_cookies_file()
-            if _cookies_path:
-                ydl_opts["cookiefile"] = _cookies_path
-                logger.debug("使用抖音 cookies 文件: %s (%d bytes)", _cookies_path, os.path.getsize(_cookies_path))
-                _dbg("cookies", f"{_cookies_path} {os.path.getsize(_cookies_path)}B")
-
-            try:
-                ydl = yt_dlp.YoutubeDL(ydl_opts)
-                info = ydl.extract_info(url_for_download, download=True)
-            except yt_dlp.utils.DownloadError as exc:
-                # yt-dlp 官方异常类型：HTTP 错误、短链失效、视频下架、cookies 过期等
-                msg = str(exc)
-                logger.warning("抖音下载失败: url=%s error=%s", source_url, msg)
-                _dbg("errtype", "DownloadError")
-                _dbg("errmsg", msg)
-                # 404/视频不存在/不可下载 → 400
-                is_bad_url = any(
-                    kw in msg.lower()
-                    for kw in (
-                        "404",
-                        "not found",
-                        "unable to download webpage",
-                        "unsupported url",
-                        "no video formats",
-                        "video unavailable",
-                        "this video isn't available",
-                    )
-                )
-                # cookies 缺失/过期 → 返回友好提示，不暴露 yt-dlp 原始错误
-                if _is_cookies_related_error(msg):
-                    logger.error("抖音 cookies 失效或缺失，需要刷新: %s", msg[:300])
-                    _detail = "抖音链接解析暂时不可用，请稍后重试或手动输入文案"
-                    if _DOUYIN_DEBUG_ERRORS:
-                        _detail = f"{_detail} [debug: {msg[:300]}]"
-                    raise HTTPException(
-                        status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-                        detail=_detail,
-                    ) from exc
-                _detail = (
-                    "无法解析该抖音链接，请确认链接有效且视频未被下架" if is_bad_url else "视频下载失败，请稍后重试"
-                )
-                if _DOUYIN_DEBUG_ERRORS:
-                    _detail = f"{_detail} [debug: {msg[:300]}]"
-                raise HTTPException(
-                    status_code=status.HTTP_400_BAD_REQUEST if is_bad_url else status.HTTP_502_BAD_GATEWAY,
-                    detail=_detail,
-                ) from exc
-            except Exception as exc:
-                msg = str(exc)
-                logger.exception("抖音视频下载异常: url=%s error=%s", source_url, msg)
-                _dbg("errtype", type(exc).__name__)
-                _dbg("errmsg", msg)
-                # cookies 相关的未知异常也走友好提示
-                if _is_cookies_related_error(msg):
-                    _detail = "抖音链接解析暂时不可用，请稍后重试或手动输入文案"
-                    if _DOUYIN_DEBUG_ERRORS:
-                        _detail = f"{_detail} [debug: {msg[:300]}]"
-                    raise HTTPException(
-                        status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-                        detail=_detail,
-                    ) from exc
-                _detail = "视频下载失败，请稍后重试"
-                if _DOUYIN_DEBUG_ERRORS:
-                    _detail = f"{_detail} [debug: {msg[:300]}]"
-                raise HTTPException(
-                    status_code=status.HTTP_502_BAD_GATEWAY,
-                    detail=_detail,
-                ) from exc
-
-            if info is None:
-                raise HTTPException(
-                    status_code=status.HTTP_400_BAD_REQUEST,
-                    detail="无法解析该抖音链接",
-                )
-
-            video_path = ydl.prepare_filename(info)
-            try:
-                duration = float(info.get("duration") or 0)
-            except (TypeError, ValueError):
-                duration = 0.0
-
-            # 校验下载的文件是否真的存在（某些 yt-dlp 版本可能 info 成功但未下载到文件）
-            if not os.path.isfile(video_path) or os.path.getsize(video_path) == 0:
-                logger.error("yt-dlp 未产生有效视频文件: path=%s", video_path)
-                raise HTTPException(
-                    status_code=status.HTTP_502_BAD_GATEWAY,
-                    detail="视频下载异常：未获取到有效文件",
-                )
-
-            # ASR 转写（兜底捕获所有异常，避免 500）
-            try:
-                text = transcribe_to_text(video_path)
-            except ASRNotConfiguredError as exc:
-                raise HTTPException(
-                    status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-                    detail=str(exc),
-                ) from exc
-            except ASRTranscriptionError as exc:
-                raise HTTPException(
-                    status_code=status.HTTP_502_BAD_GATEWAY,
-                    detail=str(exc),
-                ) from exc
-            except Exception as exc:
-                logger.exception("ASR 转写异常: path=%s", video_path)
-                raise HTTPException(
-                    status_code=status.HTTP_502_BAD_GATEWAY,
-                    detail=f"语音识别失败: {str(exc)[:200]}",
-                ) from exc
-
-    except HTTPException:
-        raise
-    except Exception as exc:
-        # 最后兜底：任何未捕获异常都转成 502/400，不允许冒泡成 500
-        logger.exception("抖音文案提取未预期异常: url=%s", source_url)
-        raise HTTPException(
-            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail=f"抖音文案提取失败: {str(exc)[:200]}",
-        ) from exc
+            text, dl_duration = _ytdlp_download_and_local_asr(
+                page_url, temp_dir, cookiefile=cookiefile
+            )
+            if dl_duration and not duration:
+                duration = dl_duration
 
     return ExtractFromDouyinResponse(
         text=text,
         duration_seconds=duration,
-        source_url=source_url,
+        source_url=page_url,
     )
 
 
-# ── 2. AI 文案改写 ───────────────────────────────────────────────────────────
+# ── 2. AI 文案改写 ────────────────────────────────────────────────────
 
 
-@router.post(
-    "/ai-rewrite",
-    response_model=AiRewriteResponse,
-)
+@router.post("/ai-rewrite", response_model=AiRewriteResponse)
 @points_gate("ai_rewrite")
 def ai_rewrite(
     request: AiRewriteRequest,
     current_user: AuthenticatedUser = Depends(get_current_user),
     db: Session = Depends(get_db_session),
-) -> AiRewriteResponse:
-    """使用豆包大模型改写文案."""
+):
     content = (request.content or "").strip()
     if not content:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail="文案内容不能为空",
-        )
-
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="文案内容不能为空")
     style = request.style or "口语化"
-
     client = get_doubao_client()
     if not client.is_available:
         raise HTTPException(
             status_code=status.HTTP_502_BAD_GATEWAY,
             detail="AI 服务不可用，请联系管理员配置豆包大模型 API Key",
         )
-
     system_prompt = (
         "你是一个专业的短视频文案改写专家。请对以下文案进行改写，"
         "要求：保留原意、口语化、适合短视频口播、调整语序避免查重。"
     )
     if style:
-        system_prompt += f"\n风格要求：{style}"
-
-    user_prompt = f"请改写以下文案：\n\n{content}"
-
+        system_prompt = system_prompt + "\n风格要求：" + style
     messages = [
         {"role": "system", "content": system_prompt},
-        {"role": "user", "content": user_prompt},
+        {"role": "user", "content": "请改写以下文案：\n\n" + content},
     ]
-
     try:
-        rewritten = client.chat_completion(
-            messages=messages,
-            temperature=0.8,
-            max_tokens=2048,
-        )
+        rewritten = client.chat_completion(messages=messages, temperature=0.8, max_tokens=2048)
     except Exception as exc:
         logger.error("AI 改写调用失败: %s", exc)
-        raise HTTPException(
-            status_code=status.HTTP_502_BAD_GATEWAY,
-            detail=f"AI 改写失败: {exc}",
-        ) from exc
-
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail="AI 改写失败: " + str(exc)) from exc
     if not rewritten:
-        raise HTTPException(
-            status_code=status.HTTP_502_BAD_GATEWAY,
-            detail="AI 改写未返回有效结果",
-        )
-
-    return AiRewriteResponse(
-        original=content,
-        rewritten=rewritten.strip(),
-        style=style,
-    )
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail="AI 改写未返回有效结果")
+    return AiRewriteResponse(original=content, rewritten=rewritten.strip(), style=style)
 
 
-# ── 3. AI 标题生成 ───────────────────────────────────────────────────────────
+# ── 3. AI 标题生成 ────────────────────────────────────────────────────
 
 
-@router.post(
-    "/ai-generate-titles",
-    response_model=AiGenerateTitlesResponse,
-)
+@router.post("/ai-generate-titles", response_model=AiGenerateTitlesResponse)
 @points_gate("ai_title")
 def ai_generate_titles(
     request: AiGenerateTitlesRequest,
     current_user: AuthenticatedUser = Depends(get_current_user),
     db: Session = Depends(get_db_session),
-) -> AiGenerateTitlesResponse:
-    """使用现有 generate_smart_titles 生成标题."""
+):
     content = (request.content or "").strip()
     if not content:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail="文案内容不能为空",
-        )
-
-    # count 限制在 1-5（Pydantic ge=1 le=5 已校验），但为兼容直接调用场景截断
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="文案内容不能为空")
     count = max(1, min(5, request.count))
-
     from app.services.ai_service import generate_smart_titles
-
-    result = generate_smart_titles(
-        description=content,
-        style="viral",
-        count=count,
-    )
-
+    result = generate_smart_titles(description=content, style="viral", count=count)
     titles = result.get("titles", [])[:count]
-
     return AiGenerateTitlesResponse(titles=titles)