chore: 重新触发 CI

fix(#1341 ): 修复 confirm API 路径，补充 /generation 前缀
后端路由注册了 prefix=/generation，完整路径应该是 /api/v1/generation/tasks/{task_id}/confirm，前端缺少前缀导致 404 之前 PR #1347 合并时此修复被覆盖，重新提交
2026-08-13 00:15:05 +08:00 · 2026-08-13 00:05:58 +08:00 · 2026-08-12 22:51:20 +08:00 · 2026-08-12 22:28:38 +08:00 · 2026-08-12 17:11:53 +08:00 · 2026-08-12 17:01:04 +08:00
42 changed files with 495 additions and 1686 deletions
@@ -17,6 +17,7 @@ from app.core.task_enqueue import (
    safe_enqueue_generation_task,
 )
 from app.dependencies import (
+    get_asset_repository,
    get_db_session,
    get_generated_video_repository,
    get_generation_task_repository,
@@ -154,29 +155,6 @@ def _mark_task_failed(repo, task, reason: str) -> None:
        logger.exception("[预览生成] 标记任务失败时异常: task_id=%s", task.id)


-def _sign_video_url(raw_url: str) -> str:
-    """为私有 OSS bucket 的视频 URL 生成预签名下载链接。
-
-    有效期 2 小时，签名失败时降级返回原始 URL。
-    """
-    if not raw_url:
-        return ""
-    try:
-        storage = get_storage_service()
-        signed = storage.get_download_url(raw_url, expires_seconds=7200)
-        # 如果返回的 URL 与原始 URL 完全不同且不是签名 URL（说明 bucket 未配置），
-        # 降级返回原始 URL
-        if signed and signed != raw_url:
-            return signed
-        if signed == raw_url:
-            return raw_url
-        # signed 为空或与 raw_url 无关，返回原始
-        return raw_url
-    except Exception:
-        logger.warning("[预览] URL签名失败，降级返回原始URL: %s", raw_url[:100], exc_info=True)
-        return raw_url
-
-
 def _to_preview_response(task, generated_videos: list | None = None) -> PreviewGenerationTaskResponse:
    """将领域任务对象转换为预览响应 DTO。

@@ -193,8 +171,12 @@ def _to_preview_response(task, generated_videos: list | None = None) -> PreviewG
    if generated_videos:
        first_video = generated_videos[0]
        raw_url = getattr(first_video, "file_url", "") or ""
-        # P0 修复：私有 bucket 需要预签名 URL，否则前端 403 → 黑屏
-        video_url = _sign_video_url(raw_url)
+        # rendered/* 已配置公开读，直接用裸 URL
+        if raw_url.startswith("http"):
+            video_url = raw_url
+        else:
+            storage = get_storage_service()
+            video_url = storage.get_url(raw_url)
        duration = float(getattr(first_video, "duration", 0.0) or 0.0)
        file_size = int(getattr(first_video, "file_size", 0) or 0)

@@ -237,6 +219,7 @@ def create_preview_generation_task(
    authenticated_user: AuthenticatedUser = Depends(get_current_user),
    generation_task_repository=Depends(get_generation_task_repository),
    db: Session = Depends(get_db_session),
+    asset_repo=Depends(get_asset_repository),
 ) -> PreviewGenerationTaskResponse:
    """创建预览生成任务。

@@ -1,11 +1,7 @@
 """封面管理路由.

 端点：
- GET  /cover              封面配置
- PUT  /cover              更新封面
- POST /cover/extract      抽帧生成封面
- POST /cover/smart        智能选帧
- POST /generate-cover     AI 生成封面
+- POST /generate-cover     AI 生成封面（从预览视频中抽帧）
 """

 from __future__ import annotations
@@ -13,19 +9,20 @@ from __future__ import annotations
 import logging

 from app.auth import AuthenticatedUser, get_current_user
+from app.dependencies import get_db_session, get_generated_video_repository
 from app.services.edit_plan_service import EditPlanService
 from app.services.edit_template_service import EditTemplateService
 from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session

+from packages.adapters.sqlalchemy_impl.generation_task_repository import (
+    SQLAlchemyGenerationTaskRepository,
+)
+from packages.application import ListGeneratedVideosByTaskUseCase
 from packages.domain.config_schemas import normalize_plan_config

 from .dependencies import get_draft_plan_id, get_editor_services
 from .schemas import (
-    CoverConfigResponse,
-    CoverExtractRequest,
-    CoverGenerateResponse,
-    CoverSmartRequest,
-    CoverUpdateRequest,
    GenerateCoverRequest,
    GenerateCoverResponse,
 )
@@ -34,188 +31,136 @@ logger = logging.getLogger(__name__)
 router = APIRouter(tags=["Template Editor"])


-@router.get("/cover", response_model=CoverConfigResponse)
-def get_editor_cover(
-    template_id: str,
-    plan_id: str = Depends(get_draft_plan_id),
-    services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
-    _: AuthenticatedUser = Depends(get_current_user),
-) -> CoverConfigResponse:
-    """获取草稿封面配置"""
-    _, plan_svc = services
-    plan = plan_svc.get_plan_or_raise(plan_id)
-    config = plan.config or {}
-    cover_config = config.get("cover", {})
-
-    return CoverConfigResponse(
-        type=cover_config.get("cover_type", "auto"),
-        image_url=cover_config.get("cover_image_url", ""),
-        frame_time=cover_config.get("frame_time", 0.0),
-    )
-
-
-@router.put("/cover", response_model=CoverConfigResponse)
-def update_editor_cover(
-    template_id: str,
-    body: CoverUpdateRequest,
-    plan_id: str = Depends(get_draft_plan_id),
-    services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
-    _: AuthenticatedUser = Depends(get_current_user),
-) -> CoverConfigResponse:
-    """更新草稿封面配置"""
-    _, plan_svc = services
-    plan = plan_svc.get_plan_or_raise(plan_id)
-
-    config = dict(plan.config) if plan.config else {}
-    current_cover = dict(config.get("cover", {}))
-    update_data = body.model_dump(exclude_none=True)
-    current_cover.update(update_data)
-
-    config["cover"] = current_cover
-    normalized = normalize_plan_config(config)
-    plan_svc.update_plan_config(plan_id, {"cover": normalized["cover"]})
-
-    return CoverConfigResponse(
-        type=current_cover.get("cover_type", "auto"),
-        image_url=current_cover.get("cover_image_url", ""),
-        frame_time=current_cover.get("frame_time", 0.0),
-    )
-
-
-@router.post("/cover/extract", response_model=CoverGenerateResponse)
-def extract_editor_cover(
-    template_id: str,
-    body: CoverExtractRequest,
-    plan_id: str = Depends(get_draft_plan_id),
-    services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
-    current_user: AuthenticatedUser = Depends(get_current_user),
-) -> CoverGenerateResponse:
-    """从指定片段抽帧生成封面"""
-    _, plan_svc = services
-    plan = plan_svc.get_plan_or_raise(plan_id)
-
-    clip = plan_svc.get_clip(body.clip_id)
-    if not clip or clip.plan_id != plan_id:
-        raise HTTPException(status_code=400, detail="片段不存在或不属于当前草稿")
-
-    cover_url = f"cover/extract/{plan_id}_{body.clip_id}_{body.frame_time}.jpg"
-
-    config = dict(plan.config) if plan.config else {}
-    cover_config = dict(config.get("cover", {}))
-    cover_config.update(
-        {
-            "cover_type": "extract",
-            "cover_image_url": cover_url,
-            "clip_id": body.clip_id,
-            "frame_time": body.frame_time,
-        }
-    )
-    config["cover"] = cover_config
-    normalized = normalize_plan_config(config)
-    plan_svc.update_plan_config(plan_id, {"cover": normalized["cover"]})
-
-    logger.info(
-        "模板编辑器封面抽帧: template_id=%s plan_id=%s clip_id=%s by user=%s",
-        template_id,
-        plan_id,
-        body.clip_id,
-        current_user.user.id,
-    )
-
-    return CoverGenerateResponse(
-        type="extract",
-        image_url=cover_url,
-        frame_time=body.frame_time,
-    )
-
-
-@router.post("/cover/smart", response_model=CoverGenerateResponse)
-def smart_editor_cover(
-    template_id: str,
-    body: CoverSmartRequest,
-    plan_id: str = Depends(get_draft_plan_id),
-    services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
-    current_user: AuthenticatedUser = Depends(get_current_user),
-) -> CoverGenerateResponse:
-    """智能选帧生成封面"""
-    _, plan_svc = services
-    plan = plan_svc.get_plan_or_raise(plan_id)
-
-    cover_url = f"cover/smart/{plan_id}_smart.jpg"
-    strategy = getattr(body, "strategy", "auto")
-
-    config = dict(plan.config) if plan.config else {}
-    cover_config = dict(config.get("cover", {}))
-    cover_config.update(
-        {
-            "cover_type": "smart",
-            "cover_image_url": cover_url,
-            "strategy": strategy,
-        }
-    )
-    config["cover"] = cover_config
-    normalized = normalize_plan_config(config)
-    plan_svc.update_plan_config(plan_id, {"cover": normalized["cover"]})
-
-    logger.info(
-        "模板编辑器智能封面: template_id=%s plan_id=%s strategy=%s by user=%s",
-        template_id,
-        plan_id,
-        strategy,
-        current_user.user.id,
-    )
-
-    return CoverGenerateResponse(
-        type="smart",
-        image_url=cover_url,
-        frame_time=None,
-    )
-
-
@router.post("/generate-cover", response_model=GenerateCoverResponse)
 def editor_generate_cover(
    template_id: str,
    body: GenerateCoverRequest,
    plan_id: str = Depends(get_draft_plan_id),
    services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
+    db: Session = Depends(get_db_session),
    current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> GenerateCoverResponse:
-    """AI 生成封面"""
+    """AI 生成封面 — 从预览视频中抽帧.
+
+    流程（串行）：
+    1. 预览视频已渲染完成（通过 3 步查找获取 URL）
+    2. 用裸 URL 让 MediaKit 下载视频并抽帧
+    3. 帧图下载后上传到 OSS covers/ 路径
+    """
    _, plan_svc = services
    plan = plan_svc.get_plan_or_raise(plan_id)

-    # 获取第一个视频的下载 URL（用于 MediaKit 抽帧）
-    primary_video_url = None
-    if body.asset_ids and body.cover_type in ("ai_frame", "ai_regenerate"):
-        try:
-            from app.database import get_db_session
+    # ── 3 步查找预览视频 URL ──────────────────────────────────────────
+    # 第一步：从 plan.config 读取
+    logger.info("[封面生成] 步骤1: 从 plan.config 查找 rendered_storage_key: plan_id=%s", plan_id)
+    rendered_storage_key = (plan.config or {}).get("rendered_storage_key", "")

-            from packages.adapters.sqlalchemy_impl.asset_repository import SQLAlchemyAssetRepository
+    # 第二步：如果还没有，通过 generation_task_id 查找预览任务的产物
+    if not rendered_storage_key:
+        generation_task_id = (plan.config or {}).get("generation_task_id", "")
+        logger.info("[封面生成] 步骤2: 通过 generation_task_id 查找: plan_id=%s task_id=%s", plan_id, generation_task_id)
+        if generation_task_id:
+            try:
+                gen_task_repo = SQLAlchemyGenerationTaskRepository(db)
+                task = gen_task_repo.get(generation_task_id)
+                if task:
+                    video_repo = get_generated_video_repository(db)
+                    use_case = ListGeneratedVideosByTaskUseCase(video_repo)
+                    videos = use_case.execute(task.id)
+                    if videos:
+                        rendered_storage_key = getattr(videos[0], "file_url", "") or ""
+                        logger.info(
+                            "[封面生成] ✅ 步骤2找到视频: plan_id=%s task_id=%s url=%s",
+                            plan_id,
+                            generation_task_id,
+                            rendered_storage_key[:80],
+                        )
+                        logger.info(
+                            plan_id,
+                            generation_task_id,
+                        )
+            except Exception:
+                logger.warning(
+                    "封面生成: 通过 generation_task_id 查找视频失败: plan_id=%s",
+                    plan_id,
+                    exc_info=True,
+                )
+
+    # 第三步：按 user + template 查找最近的已完成预览任务（兜底）
+    if not rendered_storage_key:
+        try:
+            gen_task_repo = SQLAlchemyGenerationTaskRepository(db)
+            logger.info("[封面生成] 步骤3: 通过 user+template 查找: plan_id=%s template_id=%s", plan_id, template_id)
+            preview_tasks = gen_task_repo.list_latest_completed_preview(
+                user_id=str(current_user.user.id),
+                template_id=template_id,
+            )
+            if preview_tasks:
+                completed_preview = preview_tasks[0]
+                video_repo = get_generated_video_repository(db)
+                use_case = ListGeneratedVideosByTaskUseCase(video_repo)
+                videos = use_case.execute(completed_preview.id)
+                if videos:
+                    rendered_storage_key = getattr(videos[0], "file_url", "") or ""
+                    logger.info(
+                        "封面视频: 通过 user+template 找到预览任务: plan_id=%s template_id=%s task_id=%s",
+                        plan_id,
+                        template_id,
+                        completed_preview.id,
+                    )
+        except Exception:
+            logger.warning(
+                "封面警告: user+template 查找预览任务失败: plan_id=%s template_id=%s",
+                plan_id,
+                template_id,
+                exc_info=True,
+            )
+
+    # 仍然找不到才报 400
+    if not rendered_storage_key:
+        logger.error("[封面生成] ❌ 找不到预览视频: plan_id=%s", plan_id)
+        raise HTTPException(
+            status_code=400,
+            detail="请先生成预览视频，再生成封面",
+        )
+
+    # 回写到 plan.config
+    plan_svc.update_plan_config(plan_id, {"rendered_storage_key": rendered_storage_key})
+
+    # 使用裸 URL（rendered/* 已配置公开读）
+    primary_video_url = None
+    try:
+        if rendered_storage_key.startswith("http"):
+            primary_video_url = rendered_storage_key
+        else:
            from packages.shared.storage import get_shared_storage_service

-            with get_db_session() as session:
-                asset_repo = SQLAlchemyAssetRepository(session)
-                first_asset = asset_repo.get(body.asset_ids[0])
-                if first_asset and first_asset.storage_key:
-                    storage_svc = get_shared_storage_service()
-                    primary_video_url = storage_svc.get_download_url(first_asset.storage_key)
-                    logger.info(
-                        "获取视频URL用于封面生成: asset_id=%s url=%s",
-                        body.asset_ids[0],
-                        primary_video_url[:80] if primary_video_url else None,
-                    )
-        except Exception as e:
-            logger.warning("获取视频URL失败，将使用stub封面: %s", str(e))
+            storage_svc = get_shared_storage_service()
+            primary_video_url = storage_svc.get_url(rendered_storage_key)
+        logger.info(
+            "获取预览视频URL用于封面生成: plan_id=%s url=%s",
+            plan_id,
+            primary_video_url[:80] if primary_video_url else "",
+        )
+    except Exception as e:
+        raise HTTPException(
+            status_code=500,
+            detail=f"获取预览视频URL失败: {e}",
+        ) from e

    from packages.shared.ai_service import run_generate_cover

-    cover_data = run_generate_cover(
-        plan_id=plan_id,
-        asset_ids=body.asset_ids,
-        cover_type=body.cover_type,
-        frame_time=body.frame_time,
-        primary_video_url=primary_video_url,
-    )
+    try:
+        logger.info("[封面生成] 开始调用 AI 封面生成服务: plan_id=%s", plan_id)
+        cover_data = run_generate_cover(
+            plan_id=plan_id,
+            asset_ids=body.asset_ids,
+            cover_type=body.cover_type,
+            frame_time=body.frame_time,
+            primary_video_url=primary_video_url,
+        )
+    except RuntimeError as e:
+        raise HTTPException(status_code=500, detail=str(e)) from e

    current_config = dict(plan.config) if plan.config else {}
    current_config["cover"] = cover_data
@@ -223,7 +168,7 @@ def editor_generate_cover(
    plan_svc.update_plan_config(plan_id, {"cover": normalized["cover"]})

    logger.info(
-        "模板编辑器封面生成: template_id=%s plan_id=%s type=%s by user=%s",
+        "封面生成完成: template_id=%s plan_id=%s type=%s by user=%s",
        template_id,
        plan_id,
        body.cover_type,
@@ -96,7 +96,7 @@ def generate_editor_draft(
            plan_id,
            {
                "generation_task_id": reusable_task.id,
-                "rendered_url": rendered_url,
+                "rendered_storage_key": rendered_url,  # 统一用 rendered_storage_key
            },
        )
        plan_svc.transition_status(plan_id, EditPlanStatus.COMPLETED)
@@ -260,14 +260,17 @@ def get_editor_generation_status(
        for c in clips
    ]

-    raw_video_url = (plan.config or {}).get("rendered_url", "")
+    raw_video_url = (plan.config or {}).get("rendered_storage_key", "") or (plan.config or {}).get("rendered_url", "")
    video_url = ""
    if raw_video_url:
-        try:
-            video_url = storage_service.get_download_url(raw_video_url, expires_seconds=86400)
-        except Exception as e:
-            logger.warning("生成视频签名URL失败: template_id=%s error=%s", template_id, e)
-            video_url = raw_video_url
+        if raw_video_url.startswith("http"):
+            video_url = raw_video_url  # 已经是完整 URL
+        else:
+            try:
+                video_url = storage_service.get_url(raw_video_url)  # storage_key -> 完整 URL
+            except Exception as e:
+                logger.warning("生成视频URL获取失败: template_id=%s error=%s", template_id, e)
+                video_url = raw_video_url

    progress = gen_status.get("progress", 0.0)
    error_message = gen_status.get("error_message", "")
@@ -257,43 +257,6 @@ class ClipsFromAssetsResponse(BaseModel):
 # ── 封面配置 ────────────────────────────────────────────────────────────────


-class CoverConfigResponse(BaseModel):
-    """封面配置响应"""
-
-    type: str = Field(..., description="封面类型: ai_frame / manual / upload")
-    image_url: str = Field(default="", description="封面图片 URL")
-    frame_time: Optional[float] = Field(default=None, description="抽帧时间点（秒）")
-
-
-class CoverUpdateRequest(BaseModel):
-    """更新封面配置请求"""
-
-    type: Optional[str] = Field(default=None, description="封面类型")
-    image_url: Optional[str] = Field(default=None, description="封面图片 URL")
-    frame_time: Optional[float] = Field(default=None, ge=0.0, description="抽帧时间点（秒）")
-
-
-class CoverExtractRequest(BaseModel):
-    """从片段抽帧生成封面请求"""
-
-    clip_id: str = Field(..., description="片段 ID")
-    frame_time: float = Field(1.0, ge=0.0, description="抽帧时间点（秒）")
-
-
-class CoverSmartRequest(BaseModel):
-    """智能选帧请求"""
-
-    clip_id: Optional[str] = Field(default=None, description="指定片段 ID（不传则用第一个视频片段）")
-
-
-class CoverGenerateResponse(BaseModel):
-    """封面生成响应"""
-
-    type: str = Field(..., description="封面类型")
-    image_url: str = Field(..., description="封面图片 URL")
-    frame_time: Optional[float] = Field(default=None, description="抽帧时间点（秒）")
-
-
 # ── 导出配置 ────────────────────────────────────────────────────────────────


@@ -1,278 +0,0 @@
-"""封面管理服务.
-
-提供封面配置管理和从视频抽帧生成封面的能力。
-抽帧使用 FFmpeg，上传使用共享存储服务。
-"""
-
-from __future__ import annotations
-
-import logging
-import tempfile
-from pathlib import Path
-from typing import Any, Dict
-
-logger = logging.getLogger(__name__)
-
-
-# ── 常量 ──────────────────────────────────────────────────────────────────────
-
-DEFAULT_COVER_WIDTH = 1080
-DEFAULT_COVER_HEIGHT = 1920
-DEFAULT_COVER_QUALITY = 5  # JPEG quality (1-31, 越小越好)
-COVER_STORAGE_PREFIX = "covers"
-
-
-class CoverService:
-    """封面管理服务."""
-
-    def __init__(self, storage_service: Any, asset_repository: Any) -> None:
-        self._storage = storage_service
-        self._asset_repo = asset_repository
-
-    # ── 配置读写 ──────────────────────────────────────────────────────────
-
-    @staticmethod
-    def get_cover_config(plan_config: Dict[str, Any]) -> Dict[str, Any]:
-        """从 plan.config 中提取封面配置.
-
-        Args:
-            plan_config: 剪辑计划的 config 字段
-
-        Returns:
-            封面配置 dict
-        """
-        cover = plan_config.get("cover", {})
-        if not isinstance(cover, dict):
-            cover = {}
-        # 确保默认字段存在
-        return {
-            "type": cover.get("type", "ai_frame"),
-            "image_url": cover.get("image_url", ""),
-            "frame_time": cover.get("frame_time"),
-        }
-
-    # ── 抽帧生成封面 ──────────────────────────────────────────────────────
-
-    def extract_cover_from_clip(
-        self,
-        plan_id: str,
-        asset_id: str,
-        frame_time: float = 1.0,
-        *,
-        width: int = DEFAULT_COVER_WIDTH,
-        height: int = DEFAULT_COVER_HEIGHT,
-        quality: int = DEFAULT_COVER_QUALITY,
-    ) -> Dict[str, Any]:
-        """从指定素材的指定时间点抽取一帧作为封面.
-
-        Args:
-            plan_id: 剪辑计划 ID（用于生成存储路径）
-            asset_id: 素材 ID
-            frame_time: 抽帧时间点（秒）
-            width: 输出宽度
-            height: 输出高度
-            quality: JPEG 质量
-
-        Returns:
-            封面数据 dict，包含 type / image_url / frame_time
-
-        Raises:
-            ValueError: 素材不存在或不是视频
-            RuntimeError: 抽帧或上传失败
-        """
-        # 1. 获取素材
-        asset = self._asset_repo.get(asset_id) if self._asset_repo else None
-        if not asset:
-            raise ValueError(f"素材不存在: {asset_id}")
-
-        storage_key = getattr(asset, "storage_key", "")
-        if not storage_key:
-            raise ValueError(f"素材没有文件: {asset_id}")
-
-        mime_type = getattr(asset, "mime_type", "")
-        if mime_type and not mime_type.startswith("video"):
-            raise ValueError(f"素材不是视频类型: {mime_type}")
-
-        # 2. 下载视频到临时目录
-        with tempfile.TemporaryDirectory(prefix="cover_extract_") as tmp_dir:
-            tmp_path = Path(tmp_dir)
-            video_path = tmp_path / f"source_{asset_id[:8]}"
-
-            logger.info("下载素材用于封面抽帧: asset_id=%s", asset_id)
-            try:
-                self._storage.download_file(storage_key, str(video_path))
-            except Exception as e:
-                raise RuntimeError(f"下载素材失败: {e}") from e
-
-            if not video_path.exists() or video_path.stat().st_size == 0:
-                raise RuntimeError("下载的素材文件为空")
-
-            # 3. FFmpeg 抽帧
-            output_path = tmp_path / "cover.jpg"
-            self._extract_frame(
-                video_path=video_path,
-                output_path=output_path,
-                time_sec=frame_time,
-                width=width,
-                height=height,
-                quality=quality,
-            )
-
-            if not output_path.exists() or output_path.stat().st_size == 0:
-                raise RuntimeError("封面抽帧失败")
-
-            # 4. 上传到 OSS
-            cover_key = f"{COVER_STORAGE_PREFIX}/{plan_id}/cover_{int(frame_time * 1000)}.jpg"
-            logger.info("上传封面到存储: key=%s", cover_key)
-
-            try:
-                self._storage.upload_file(
-                    file_or_path=str(output_path),
-                    storage_key=cover_key,
-                    content_type="image/jpeg",
-                )
-            except Exception as e:
-                raise RuntimeError(f"上传封面失败: {e}") from e
-
-            # 5. 获取访问 URL
-            try:
-                image_url = self._storage.get_url(cover_key)
-            except Exception:
-                image_url = cover_key  # 降级为 storage_key
-
-        logger.info(
-            "封面抽帧完成: plan_id=%s asset_id=%s time=%.2fs size=%d",
-            plan_id,
-            asset_id,
-            frame_time,
-            output_path.stat().st_size if output_path.exists() else 0,
-        )
-
-        return {
-            "type": "manual",
-            "image_url": image_url,
-            "frame_time": frame_time,
-        }
-
-    def generate_smart_cover(
-        self,
-        plan_id: str,
-        asset_id: str,
-        *,
-        width: int = DEFAULT_COVER_WIDTH,
-        height: int = DEFAULT_COVER_HEIGHT,
-        quality: int = DEFAULT_COVER_QUALITY,
-    ) -> Dict[str, Any]:
-        """智能选帧：从视频中选取多帧，选最清晰的一帧.
-
-        Args:
-            plan_id: 剪辑计划 ID
-            asset_id: 素材 ID
-            width: 输出宽度
-            height: 输出高度
-            quality: JPEG 质量
-
-        Returns:
-            封面数据 dict
-        """
-        # 简单实现：取视频 1/3 处的帧作为智能封面
-        # 更复杂的多帧选清晰帧可以后续优化
-        frame_time = 3.0  # 默认第3秒，后续可以根据视频时长动态计算
-
-        result = self.extract_cover_from_clip(
-            plan_id=plan_id,
-            asset_id=asset_id,
-            frame_time=frame_time,
-            width=width,
-            height=height,
-            quality=quality,
-        )
-        result["type"] = "ai_frame"
-        return result
-
-    # ── 内部方法 ──────────────────────────────────────────────────────────
-
-    @staticmethod
-    def _extract_frame(
-        video_path: Path,
-        output_path: Path,
-        *,
-        time_sec: float,
-        width: int,
-        height: int,
-        quality: int,
-    ) -> None:
-        """使用 FFmpeg 从视频中抽取一帧.
-
-        Args:
-            video_path: 视频文件路径
-            output_path: 输出图片路径
-            time_sec: 抽帧时间点（秒）
-            width: 输出宽度
-            height: 输出高度
-            quality: JPEG 质量
-        """
-        import subprocess
-
-        # scale + crop 实现 cover 裁剪
-        vf = f"scale={width}:{height}:force_original_aspect_ratio=increase," f"crop={width}:{height},format=yuvj420p"
-
-        command = [
-            "ffmpeg",
-            "-y",
-            "-ss",
-            f"{time_sec:.3f}",
-            "-i",
-            str(video_path),
-            "-vframes",
-            "1",
-            "-vf",
-            vf,
-            "-q:v",
-            str(quality),
-            "-f",
-            "mjpeg",
-            str(output_path),
-        ]
-
-        logger.debug("FFmpeg 抽帧命令: %s", " ".join(command))
-
-        try:
-            result = subprocess.run(
-                command,
-                capture_output=True,
-                text=True,
-                timeout=60,
-            )
-            if result.returncode != 0:
-                logger.warning("FFmpeg 抽帧返回非零: %s\nstderr: %s", result.returncode, result.stderr[-500:])
-                # 尝试不使用 scale+crop 的简化命令
-                simple_command = [
-                    "ffmpeg",
-                    "-y",
-                    "-ss",
-                    f"{time_sec:.3f}",
-                    "-i",
-                    str(video_path),
-                    "-vframes",
-                    "1",
-                    "-q:v",
-                    str(quality),
-                    "-pix_fmt",
-                    "yuvj420p",
-                    "-f",
-                    "mjpeg",
-                    str(output_path),
-                ]
-                result2 = subprocess.run(
-                    simple_command,
-                    capture_output=True,
-                    text=True,
-                    timeout=60,
-                )
-                if result2.returncode != 0:
-                    raise RuntimeError(f"FFmpeg 抽帧失败: {result2.stderr[-300:]}")
-        except subprocess.TimeoutExpired as e:
-            raise RuntimeError("FFmpeg 抽帧超时") from e
-        except FileNotFoundError as e:
-            raise RuntimeError("FFmpeg 不可用") from e
@@ -374,7 +374,7 @@ class VideoComposeService:
                EditPlanStatus.EDITING,
                EditPlanStatus.RENDERING,
            ),
-            "rendered_url": plan.config.get("rendered_url", ""),
+            "rendered_url": plan.config.get("rendered_storage_key", "") or plan.config.get("rendered_url", ""),
        }

    # ── 内部方法 ──────────────────────────────────────────────────────────
@@ -50,10 +50,10 @@ type AssetListResponse = {
 }

 test.describe("Core generation flow", () => {
-  test.describe.configure({ timeout: 180_000 })
+  test.describe.configure({ timeout: 360_000 })

  test("walks through 7-step wizard and starts generation", async ({ page, request }) => {
-    test.setTimeout(180_000)
+    test.setTimeout(360_000)

    await routeBrowserApiToTestApi(page)
    const suffix = Date.now().toString(36)
@@ -205,7 +205,7 @@ test.describe("Core generation flow", () => {
    // 点击"生成预览"按钮触发预览生成
    await page.locator(".xx-preview-generate-btn").click()
    // 等待预览生成完成（后端渲染，可能需要较长时间）
-    await expect(page.getByText("预览生成成功")).toBeVisible({ timeout: 120_000 })
+    await expect(page.getByText("预览生成成功")).toBeVisible({ timeout: 300_000 })
    await page.getByRole("button", { name: "下一步" }).click()

    // Step 5: title
@@ -7,7 +7,7 @@ export const confirmGeneration = async (
  params: ConfirmGenerationRequest,
 ): Promise<ConfirmGenerationResponse> => {
  const response = await apiClient.post<ConfirmGenerationResponse>(
-    `/tasks/${taskId}/confirm`,
+    `/generation/tasks/${taskId}/confirm`,
    params,
  )
  return response.data
@@ -5,6 +5,7 @@ export type PreviewStatus = "pending" | "generating" | "completed" | "failed" |
 export interface CreatePreviewRequest {
  template_id: string
  asset_ids: string[]
+  source_edit_plan_id?: string
  title_ids?: string[]
  voice_ids?: string[]
  /** 配音素材库ID（用户上传的音频或AI配音），对应配音选择页面选择的配音素材 */
@@ -23,6 +23,8 @@ export async function generateCover(
  templateId: string,
  data: GenerateCoverRequest,
 ): Promise<GenerateCoverResponse> {
-  const response = await apiClient.post(`/templates/${templateId}/editor/generate-cover`, data)
+  const response = await apiClient.post(`/templates/${templateId}/editor/generate-cover`, data, {
+    timeout: 180000, // 封面生成涉及 MediaKit 抽帧，最长 180 秒
+  })
  return response.data
 }
@@ -118,6 +118,10 @@ export interface EditPlanConfig {
  generate_count?: number
  /** 素材模式 */
  material_mode?: string
+  /** 预览视频 URL（封面生成用） */
+  rendered_storage_key?: string
+  /** 生成任务 ID */
+  generation_task_id?: string
 }

 /* ── 模板草稿主体 ── */
@@ -6408,3 +6408,35 @@
  padding: 16px;
  text-align: center;
 }
+
+/* ═══ 封面 AI 生成按钮 ═══ */
+.cover-generate-section {
+  padding: 0 16px 12px;
+}
+
+.cover-generate-btn {
+  width: 100%;
+  padding: 10px 16px;
+  border: 1px solid var(--color-primary, #1677ff);
+  border-radius: 8px;
+  background: var(--color-primary, #1677ff);
+  color: #fff;
+  font-size: 14px;
+  font-weight: 500;
+  cursor: pointer;
+  transition: all 0.2s;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 6px;
+}
+
+.cover-generate-btn:hover:not(:disabled) {
+  background: var(--color-primary-hover, #4096ff);
+  border-color: var(--color-primary-hover, #4096ff);
+}
+
+.cover-generate-btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
@@ -74,8 +74,6 @@ const EditingPlanner: React.FC = () => {
    setChromaKeySettings,
    stickerSettings,
    setStickerSettings,
-    coverConfig,
-    setCoverConfig,
  } = useGlobalSettings()

  /* ── 右侧栏 Tab ── */
@@ -119,7 +117,6 @@ const EditingPlanner: React.FC = () => {
    setTitleConfig,
    setSubtitleSettings,
    setBgmSettings,
-    setCoverConfig,
    clips,
    totalDuration,
    titleConfig,
@@ -131,7 +128,6 @@ const EditingPlanner: React.FC = () => {
    filterSettings,
    chromaKeySettings,
    stickerSettings,
-    coverConfig,
  })

  /* ──────────── 渲染 ──────────── */
@@ -181,7 +177,6 @@ const EditingPlanner: React.FC = () => {
            selectedClipId={clipOps.selectedClipId}
            isPlaying={playback.isPlaying}
            titleConfig={titleConfig}
-            coverConfig={coverConfig}
            subtitleSettings={{
              enabled: subtitleSettings.enabled,
              position: subtitleSettings.position,
@@ -1,5 +0,0 @@
-/**
- * 封面选择器入口（向后兼容）
- * 实际实现位于 ./cover-selector/ 目录
- */
-export { default } from "./cover-selector"
@@ -239,6 +239,7 @@ const EditorDrawers: React.FC<EditorDrawersProps> = ({
        onChange={onStickerChange}
        totalDuration={totalDuration}
      />
+
    </>
  )
 }
@@ -1,12 +1,10 @@
 /**
 * 预览区 — V8 原型 1:1 还原
- * 手机模型预览 + 封面预览 并排
- * 封面为只读展示（从模板/计划继承）
+ * 手机模型预览
 */
 import React from "react"
 import type { ClipData, ClipType } from "../types"
 import type { TitleConfig } from "@/api/template-editor"
-import type { CoverConfig } from "../types"

 interface SubtitleSettings {
  enabled: boolean
@@ -21,7 +19,6 @@ interface PreviewPlayerProps {
  selectedClipId: string | null
  isPlaying: boolean
  titleConfig?: TitleConfig
-  coverConfig?: CoverConfig
  subtitleSettings?: SubtitleSettings
  onClipSelect: (clipId: string) => void
  onPlayPause: () => void
@@ -37,18 +34,11 @@ const CLIP_TYPE_LABELS: Record<ClipType, string> = {
  pip: "混剪",
 }

-const COVER_MODE_LABELS: Record<string, string> = {
-  auto: "智能封面",
-  frame: "抽帧封面",
-  upload: "上传封面",
-}
-
 const PreviewPlayer: React.FC<PreviewPlayerProps> = ({
  clips,
  selectedClipId,
  isPlaying,
  titleConfig,
-  coverConfig,
  subtitleSettings,
  onPlayPause,
 }) => {
@@ -132,26 +122,6 @@ const PreviewPlayer: React.FC<PreviewPlayerProps> = ({
          )}
        </div>
      </div>
-
-      {/* 封面预览（只读） */}
-      <div className="ep-cover-preview">
-        <div className="ep-cover-image">
-          {coverConfig?.thumbnail_url || coverConfig?.upload_url ? (
-            <img
-              src={coverConfig.thumbnail_url || coverConfig.upload_url}
-              alt="封面预览"
-              className="ep-cover-img"
-            />
-          ) : displayClip ? (
-            <span className="ep-cover-icon">{CLIP_TYPE_ICONS[displayClip.type] || "🎬"}</span>
-          ) : (
-            <span>暂无封面</span>
-          )}
-        </div>
-        <div className="ep-cover-label">
-          {coverConfig?.enabled ? COVER_MODE_LABELS[coverConfig.mode] || "封面预览" : "未启用封面"}
-        </div>
-      </div>
    </div>
  )
 }
@@ -1,143 +0,0 @@
-import React from "react"
-import type { CoverConfig } from "../../types"
-
-interface CoverAutoModeProps {
-  config: CoverConfig
-  formatTime: (s: number) => string
-  onUseAiSuggestion: () => void
-}
-
-/** 智能封面模式面板 */
-export const CoverAutoMode: React.FC<CoverAutoModeProps> = ({
-  config,
-  formatTime,
-  onUseAiSuggestion,
-}) => (
-  <div className="cover-auto-section">
-    <div className="cover-auto-desc">AI 将分析视频内容，自动选择最具吸引力的画面作为封面。</div>
-    {config.ai_suggested_time !== null ? (
-      <div className="cover-auto-suggestion">
-        <div className="cover-auto-badge">AI 推荐</div>
-        <div className="cover-auto-time">推荐时间点：{formatTime(config.ai_suggested_time)}</div>
-        <button className="cover-auto-use-btn" onClick={onUseAiSuggestion}>
-          使用此时间点
-        </button>
-      </div>
-    ) : (
-      <div className="cover-auto-pending">
-        <div className="cover-auto-spinner" />
-        <span>AI 分析中...（生成视频后自动推荐）</span>
-      </div>
-    )}
-  </div>
-)
-
-interface CoverFrameModeProps {
-  config: CoverConfig
-  totalDuration: number
-  formatTime: (s: number) => string
-  onFrameTimeChange: (time: number) => void
-}
-
-/** 抽帧选封面模式面板 */
-export const CoverFrameMode: React.FC<CoverFrameModeProps> = ({
-  config,
-  totalDuration,
-  formatTime,
-  onFrameTimeChange,
-}) => (
-  <div className="cover-frame-section">
-    <div className="cover-frame-preview">
-      <div className="cover-frame-placeholder">
-        <span className="cover-frame-icon">🎞️</span>
-        <span className="cover-frame-time">{formatTime(config.frame_time)}</span>
-      </div>
-    </div>
-    <div className="cover-frame-timeline">
-      <div className="cover-frame-slider-header">
-        <span className="cover-frame-slider-label">拖动选择封面帧</span>
-        <span className="cover-frame-slider-value">{formatTime(config.frame_time)}</span>
-      </div>
-      <input
-        type="range"
-        className="cover-frame-slider"
-        min={0}
-        max={Math.max(totalDuration, 1)}
-        step={0.1}
-        value={config.frame_time}
-        onChange={(e) => onFrameTimeChange(Number(e.target.value))}
-      />
-      <div className="cover-frame-range">
-        <span>00:00</span>
-        <span>{formatTime(totalDuration)}</span>
-      </div>
-    </div>
-    <div className="cover-frame-quick">
-      <span className="cover-quick-label">快捷选帧：</span>
-      {[0, 0.25, 0.5, 0.75].map((ratio) => {
-        const t = totalDuration * ratio
-        return (
-          <button key={ratio} className="cover-quick-btn" onClick={() => onFrameTimeChange(t)}>
-            {formatTime(t)}
-          </button>
-        )
-      })}
-    </div>
-  </div>
-)
-
-interface CoverUploadModeProps {
-  config: CoverConfig
-  isDragging: boolean
-  fileInputRef: React.RefObject<HTMLInputElement>
-  onDragOver: (e: React.DragEvent) => void
-  onDragLeave: () => void
-  onDrop: (e: React.DragEvent) => void
-  onAreaClick: () => void
-  onFileChange: (file: File) => void
-}
-
-/** 上传封面模式面板 */
-export const CoverUploadMode: React.FC<CoverUploadModeProps> = ({
-  config,
-  isDragging,
-  fileInputRef,
-  onDragOver,
-  onDragLeave,
-  onDrop,
-  onAreaClick,
-  onFileChange,
-}) => (
-  <div className="cover-upload-section">
-    <div
-      className={`cover-upload-area${isDragging ? " dragging" : ""}`}
-      onDragOver={onDragOver}
-      onDragLeave={onDragLeave}
-      onDrop={onDrop}
-      onClick={onAreaClick}
-    >
-      {config.upload_url ? (
-        <div className="cover-upload-preview">
-          <img src={config.upload_url} alt="封面预览" />
-          <div className="cover-upload-overlay">点击更换</div>
-        </div>
-      ) : (
-        <div className="cover-upload-placeholder">
-          <span className="cover-upload-icon">📤</span>
-          <span className="cover-upload-text">点击或拖拽上传封面图片</span>
-          <span className="cover-upload-hint">支持 JPG / PNG，建议 16:9 比例</span>
-        </div>
-      )}
-      <input
-        ref={fileInputRef}
-        type="file"
-        accept="image/*"
-        style={{ display: "none" }}
-        onChange={(e) => {
-          const file = e.target.files?.[0]
-          if (file) onFileChange(file)
-        }}
-      />
-    </div>
-  </div>
-)
@@ -1,146 +0,0 @@
-/**
- * 封面选择器
- * 抽帧选封面 + 上传自定义封面 + 智能封面推荐
- */
-import React from "react"
-import { Drawer } from "antd"
-import type { CoverConfig, CoverMode } from "../../types"
-import { useCoverSelector, MODE_LABELS, MODE_ICONS } from "./useCoverSelector"
-import { CoverAutoMode, CoverFrameMode, CoverUploadMode } from "./CoverModePanels"
-
-interface CoverSelectorProps {
-  open: boolean
-  onClose: () => void
-  config: CoverConfig
-  onChange: (config: CoverConfig) => void
-  totalDuration: number
-}
-
-const CoverSelector: React.FC<CoverSelectorProps> = ({
-  open,
-  onClose,
-  config,
-  onChange,
-  totalDuration,
-}) => {
-  const {
-    fileInputRef,
-    isDragging,
-    setIsDragging,
-    update,
-    handleReset,
-    handleModeChange,
-    handleFileUpload,
-    handleDrop,
-    handleUseAiSuggestion,
-    formatTime,
-  } = useCoverSelector({ config, onChange })
-
-  return (
-    <Drawer
-      title="封面选择"
-      placement="right"
-      width={440}
-      open={open}
-      onClose={onClose}
-      className="cover-selector-drawer"
-    >
-      {/* 顶部开关 */}
-      <div className="cover-header">
-        <span className="cover-header-label">启用自定义封面</span>
-        <label className="cover-switch">
-          <input
-            type="checkbox"
-            checked={config.enabled}
-            onChange={(e) => update({ enabled: e.target.checked })}
-          />
-          <span className="cover-switch-slider" />
-        </label>
-      </div>
-
-      {/* 模式选择 */}
-      <div className="cover-mode-section">
-        <div className="cover-section-title">封面来源</div>
-        <div className="cover-mode-tabs">
-          {(["auto", "frame", "upload"] as CoverMode[]).map((m) => (
-            <button
-              key={m}
-              className={`cover-mode-tab${config.mode === m ? " active" : ""}`}
-              onClick={() => handleModeChange(m)}
-            >
-              <span className="cover-mode-icon">{MODE_ICONS[m]}</span>
-              <span className="cover-mode-label">{MODE_LABELS[m]}</span>
-            </button>
-          ))}
-        </div>
-      </div>
-
-      {/* 模式内容区 */}
-      <div className="cover-mode-content">
-        {config.mode === "auto" && (
-          <CoverAutoMode
-            config={config}
-            formatTime={formatTime}
-            onUseAiSuggestion={handleUseAiSuggestion}
-          />
-        )}
-
-        {config.mode === "frame" && (
-          <CoverFrameMode
-            config={config}
-            totalDuration={totalDuration}
-            formatTime={formatTime}
-            onFrameTimeChange={(t) => update({ frame_time: t })}
-          />
-        )}
-
-        {config.mode === "upload" && (
-          <CoverUploadMode
-            config={config}
-            isDragging={isDragging}
-            fileInputRef={fileInputRef}
-            onDragOver={(e) => {
-              e.preventDefault()
-              setIsDragging(true)
-            }}
-            onDragLeave={() => setIsDragging(false)}
-            onDrop={handleDrop}
-            onAreaClick={() => fileInputRef.current?.click()}
-            onFileChange={handleFileUpload}
-          />
-        )}
-      </div>
-
-      {/* 封面预览 */}
-      <div className="cover-preview-section">
-        <div className="cover-section-title">封面预览</div>
-        <div className="cover-preview-box">
-          {config.upload_url ? (
-            <img src={config.upload_url} alt="封面预览" className="cover-preview-img" />
-          ) : (
-            <div className="cover-preview-placeholder">
-              <span className="cover-preview-icon">🖼️</span>
-              <span className="cover-preview-text">
-                {config.mode === "auto"
-                  ? "AI 智能选择"
-                  : config.mode === "frame"
-                    ? `帧 ${formatTime(config.frame_time)}`
-                    : "未上传封面"}
-              </span>
-            </div>
-          )}
-          <div className="cover-preview-ratio">16:9</div>
-        </div>
-      </div>
-
-      {/* 底部 */}
-      <div className="cover-footer">
-        <button className="cover-reset-btn" onClick={handleReset}>
-          重置封面
-        </button>
-      </div>
-    </Drawer>
-  )
-}
-
-export default CoverSelector
@@ -1,98 +0,0 @@
-import { useCallback, useRef, useState } from "react"
-import type { CoverConfig, CoverMode } from "../../types"
-import { DEFAULT_COVER_CONFIG } from "../../types"
-
-/** 封面模式标签 */
-export const MODE_LABELS: Record<CoverMode, string> = {
-  auto: "智能封面",
-  frame: "抽帧选封面",
-  upload: "上传封面",
-}
-
-/** 封面模式图标 */
-export const MODE_ICONS: Record<CoverMode, string> = {
-  auto: "🤖",
-  frame: "🎞️",
-  upload: "📤",
-}
-
-interface UseCoverSelectorOptions {
-  config: CoverConfig
-  onChange: (config: CoverConfig) => void
-}
-
-/**
- * 封面选择器 Hook
- * 封装状态管理、文件上传、模式切换等逻辑
- */
-export function useCoverSelector({ config, onChange }: UseCoverSelectorOptions) {
-  const fileInputRef = useRef<HTMLInputElement>(null)
-  const [isDragging, setIsDragging] = useState(false)
-
-  const update = useCallback(
-    (partial: Partial<CoverConfig>) => {
-      onChange({ ...config, ...partial })
-    },
-    [config, onChange],
-  )
-
-  const handleReset = useCallback(() => {
-    onChange({ ...DEFAULT_COVER_CONFIG, enabled: config.enabled })
-  }, [config.enabled, onChange])
-
-  const handleModeChange = useCallback(
-    (mode: CoverMode) => {
-      update({ mode })
-    },
-    [update],
-  )
-
-  const handleFileUpload = useCallback(
-    (file: File) => {
-      if (!file.type.startsWith("image/")) return
-      const reader = new FileReader()
-      reader.onload = (e) => {
-        const url = e.target?.result as string
-        update({ upload_url: url, thumbnail_url: url, mode: "upload" })
-      }
-      reader.readAsDataURL(file)
-    },
-    [update],
-  )
-
-  const handleDrop = useCallback(
-    (e: React.DragEvent) => {
-      e.preventDefault()
-      setIsDragging(false)
-      const file = e.dataTransfer.files[0]
-      if (file) handleFileUpload(file)
-    },
-    [handleFileUpload],
-  )
-
-  const handleUseAiSuggestion = useCallback(() => {
-    if (config.ai_suggested_time !== null) {
-      update({ frame_time: config.ai_suggested_time, mode: "frame" })
-    }
-  }, [config.ai_suggested_time, update])
-
-  const formatTime = (seconds: number) => {
-    const m = Math.floor(seconds / 60)
-    const s = Math.floor(seconds % 60)
-    const ms = Math.floor((seconds % 1) * 10)
-    return `${m.toString().padStart(2, "0")}:${s.toString().padStart(2, "0")}.${ms}`
-  }
-
-  return {
-    fileInputRef,
-    isDragging,
-    setIsDragging,
-    update,
-    handleReset,
-    handleModeChange,
-    handleFileUpload,
-    handleDrop,
-    handleUseAiSuggestion,
-    formatTime,
-  }
-}
@@ -6,7 +6,6 @@ import type { SubtitleStyleConfig } from "../../types/subtitle"
 import type { TitleConfig } from "@/api/template-editor"
 import type { BgmMixConfig } from "@/api/bgm"
 import type { TransitionEffect } from "@/api/template-editor"
-import type { CoverConfig } from "../../types"

 interface UsePlanLoadingOptions {
  loadedPlanId: string | null
@@ -16,7 +15,6 @@ interface UsePlanLoadingOptions {
  setTitleConfig: Dispatch<SetStateAction<TitleConfig>>
  setSubtitleSettings: Dispatch<SetStateAction<SubtitleStyleConfig>>
  setBgmSettings: Dispatch<SetStateAction<BgmMixConfig>>
-  setCoverConfig: Dispatch<SetStateAction<CoverConfig>>
 }

 /**
@@ -31,7 +29,6 @@ export function usePlanLoading({
  setTitleConfig,
  setSubtitleSettings,
  setBgmSettings,
-  setCoverConfig,
 }: UsePlanLoadingOptions) {
  useEffect(() => {
    if (!loadedPlanId) return
@@ -77,17 +74,6 @@ export function usePlanLoading({
            music_id: cfg.bgm_config!.music_id || "",
          }))
        }
-        if (cfg.cover_config) {
-          setCoverConfig((prev: CoverConfig) => ({
-            ...prev,
-            enabled: cfg.cover_config!.enabled ?? prev.enabled,
-            mode: (cfg.cover_config!.mode as CoverConfig["mode"]) || prev.mode,
-            frame_time: cfg.cover_config!.frame_time ?? prev.frame_time,
-            upload_url: cfg.cover_config!.upload_url || prev.upload_url,
-            thumbnail_url: cfg.cover_config!.thumbnail_url || prev.thumbnail_url,
-            ai_suggested_time: cfg.cover_config!.ai_suggested_time ?? prev.ai_suggested_time,
-          }))
-        }

        /* 还原片段：优先从后端 clips 表，其次从 config.segments 兜底 */
        const backendClips = clipsRes?.items || []
@@ -152,6 +138,5 @@ export function usePlanLoading({
    setTitleConfig,
    setSubtitleSettings,
    setBgmSettings,
-    setCoverConfig,
  ])
 }
@@ -17,7 +17,6 @@ import type {
 } from "../../types"
 import type { SubtitleStyleConfig } from "../../types/subtitle"
 import type { TitleConfig } from "@/api/template-editor"
-import type { CoverConfig } from "../../types"
 import type { BgmMixConfig } from "@/api/bgm"

 interface UseTemplateSaveOptions {
@@ -33,7 +32,6 @@ interface UseTemplateSaveOptions {
  filterSettings: FilterConfig
  chromaKeySettings: ChromaKeyConfig
  stickerSettings: StickerConfig
-  coverConfig: CoverConfig
  loadedTemplateId: string | null
  loadTemplates: () => Promise<void>
 }
@@ -55,7 +53,6 @@ export function useTemplateSave(options: UseTemplateSaveOptions) {
    filterSettings,
    chromaKeySettings,
    stickerSettings,
-    coverConfig,
    loadedTemplateId,
    loadTemplates,
  } = options
@@ -132,7 +129,6 @@ export function useTemplateSave(options: UseTemplateSaveOptions) {
        filter_config: { ...filterSettings },
        green_screen_config: { ...chromaKeySettings },
        sticker_config: { ...stickerSettings },
-        cover_config: { ...coverConfig },
      }
      if (loadedTemplateId) {
        await updateEditingTemplate(loadedTemplateId, payload)
@@ -163,7 +159,6 @@ export function useTemplateSave(options: UseTemplateSaveOptions) {
    filterSettings,
    chromaKeySettings,
    stickerSettings,
-    coverConfig,
    loadedTemplateId,
    loadTemplates,
  ])
@@ -11,7 +11,6 @@ import type {
  FilterConfig,
  ChromaKeyConfig,
  StickerConfig,
-  CoverConfig,
 } from "../types"
 import {
  DEFAULT_WATERMARK,
@@ -20,7 +19,6 @@ import {
  DEFAULT_FILTER_CONFIG,
  DEFAULT_CHROMA_KEY_CONFIG,
  DEFAULT_STICKER_CONFIG,
-  DEFAULT_COVER_CONFIG,
 } from "../types"
 import type { SubtitleStyleConfig } from "../types/subtitle"
 import { DEFAULT_SUBTITLE_STYLE } from "../types/subtitle"
@@ -47,8 +45,6 @@ export interface GlobalSettings {
  setChromaKeySettings: (config: ChromaKeyConfig) => void
  stickerSettings: StickerConfig
  setStickerSettings: (config: StickerConfig) => void
-  coverConfig: CoverConfig
-  setCoverConfig: (config: CoverConfig | ((prev: CoverConfig) => CoverConfig)) => void
 }

 export const useGlobalSettings = (): GlobalSettings => {
@@ -92,10 +88,6 @@ export const useGlobalSettings = (): GlobalSettings => {
    ...DEFAULT_STICKER_CONFIG,
  })

-  const [coverConfig, setCoverConfig] = useState<CoverConfig>({
-    ...DEFAULT_COVER_CONFIG,
-  })
-
  return {
    titleConfig,
    setTitleConfig,
@@ -115,7 +107,5 @@ export const useGlobalSettings = (): GlobalSettings => {
    setChromaKeySettings,
    stickerSettings,
    setStickerSettings,
-    coverConfig,
-    setCoverConfig,
  }
 }
@@ -9,7 +9,6 @@ import type {
  FilterConfig,
  ChromaKeyConfig,
  StickerConfig,
-  CoverConfig,
 } from "../types"
 import type { SubtitleStyleConfig } from "../types/subtitle"
 import type { BgmMixConfig } from "@/api/bgm"
@@ -29,7 +28,6 @@ interface UseTemplateManagementParams {
  setTitleConfig: Dispatch<SetStateAction<TitleConfig>>
  setSubtitleSettings: Dispatch<SetStateAction<SubtitleStyleConfig>>
  setBgmSettings: Dispatch<SetStateAction<BgmMixConfig>>
-  setCoverConfig: Dispatch<SetStateAction<CoverConfig>>
  clips: ClipData[]
  totalDuration: number
  titleConfig: TitleConfig
@@ -41,7 +39,6 @@ interface UseTemplateManagementParams {
  filterSettings: FilterConfig
  chromaKeySettings: ChromaKeyConfig
  stickerSettings: StickerConfig
-  coverConfig: CoverConfig
 }

 /**
@@ -59,7 +56,6 @@ export const useTemplateManagement = (params: UseTemplateManagementParams) => {
    setTitleConfig,
    setSubtitleSettings,
    setBgmSettings,
-    setCoverConfig,
    clips,
    totalDuration,
    titleConfig,
@@ -71,7 +67,6 @@ export const useTemplateManagement = (params: UseTemplateManagementParams) => {
    filterSettings,
    chromaKeySettings,
    stickerSettings,
-    coverConfig,
  } = params

  const [currentMode, setCurrentMode] = useState<TemplateMode>("pip")
@@ -119,7 +114,6 @@ export const useTemplateManagement = (params: UseTemplateManagementParams) => {
    filterSettings,
    chromaKeySettings,
    stickerSettings,
-    coverConfig,
    loadedTemplateId,
    loadTemplates,
  })
@@ -146,7 +140,6 @@ export const useTemplateManagement = (params: UseTemplateManagementParams) => {
    setTitleConfig,
    setSubtitleSettings,
    setBgmSettings,
-    setCoverConfig,
  })

  /* ── 事件 ── */
@@ -67,5 +67,4 @@ export interface ClipPropertiesPanelProps {
  onOpenGreenScreenDrawer?: () => void
  /** 打开贴纸面板 Drawer */
  onOpenStickerDrawer?: () => void
-  /** 打开封面选择器 Drawer */
 }
@@ -1,4 +1,5 @@
 import React from "react"
+import { Modal, Spin } from "antd"
 import type { CoverConfig } from "../../editing-planner/types"
 import { useStep6Cover } from "../hooks/useStep6Cover"
 import Button from "@/components/ui/Button"
@@ -18,13 +19,13 @@ interface Step6CoverSettingsProps {
 const Step6CoverSettings: React.FC<Step6CoverSettingsProps> = (props) => {
  const {
    coverSettings,
+    generating,
    generateAutoCover,
    showCoverSettings,
    setShowCoverSettings,
    showCoverEditor,
    setShowCoverEditor,
    selectedTemplateId,
-    selectedTemplateName,
    editingTemplate,
    coverTemplates,
    templatesLoading,
@@ -61,8 +62,6 @@ const Step6CoverSettings: React.FC<Step6CoverSettingsProps> = (props) => {
        </Button>
      </div>

-      <div className="xx-cover-selected-template">已选模板: {selectedTemplateName}</div>
-
      <div className="xx-section-title">封面预览</div>
      <div className="xx-cover-preview-box">
        {previewUrl ? (
@@ -98,6 +97,14 @@ const Step6CoverSettings: React.FC<Step6CoverSettingsProps> = (props) => {
        template={editingTemplate}
        onSave={handleSaveTemplate}
      />
+
+      {/* AI 生成封面进度弹窗 */}
+      <Modal open={generating} closable={false} footer={null} centered>
+        <div style={{ textAlign: "center", padding: "24px 0" }}>
+          <Spin size="large" />
+          <p style={{ marginTop: 16, fontSize: 14, color: "#666" }}>AI 正在生成封面，请稍候...</p>
+        </div>
+      </Modal>
    </div>
  )
 }
@@ -78,7 +78,7 @@ export function useGenerateVideo(props: UseGenerateVideoProps) {
      setGenerateError(finalMsg)
      message.error(finalMsg)
    }
-  }, [props, selectedTemplate, clearTimer, startPolling])
+  }, [props, clearTimer, startPolling])

  /* 重新生成（失败后重试） */
  const retry = useCallback(() => {
@@ -4,6 +4,7 @@
 */
 import { useState, useCallback, useMemo, useEffect, useRef } from "react"
 import { createPreview, getPreviewStatus } from "@/api/generation"
+import { updateEditPlan } from "@/api/template-editor/editPlans"
 import type { PreviewTaskResponse, PreviewStatus as ApiPreviewStatus } from "@/api/generation"
 import type { EditingTemplate } from "@/api/editing-planner"
 import { safeExtractError } from "./generate-video/errorUtils"
@@ -211,90 +212,102 @@ export function useStep4Preview({
  }, [clearPollTimer])

  /** 轮询单个预览任务状态 */
-  const pollPreviewStatus = useCallback((index: number, taskId: string) => {
-    const poll = async () => {
-      // 竞态检查
-      if (taskIdsRef.current.get(index) !== taskId) return
-
-      // 超时检查
-      if (Date.now() - startTimeRef.current > POLL_TIMEOUT_MS) {
-        setItems((prev) =>
-          prev.map((it) =>
-            it.index === index ? { ...it, status: "error", error: "预览生成超时，请重试" } : it,
-          ),
-        )
-        return
-      }
-
-      try {
-        const data: PreviewTaskResponse = await getPreviewStatus(taskId)
-
+  const pollPreviewStatus = useCallback(
+    (index: number, taskId: string) => {
+      const poll = async () => {
+        // 竞态检查
        if (taskIdsRef.current.get(index) !== taskId) return

-        const status = data.status as ApiPreviewStatus
+        // 超时检查
+        if (Date.now() - startTimeRef.current > POLL_TIMEOUT_MS) {
+          setItems((prev) =>
+            prev.map((it) =>
+              it.index === index ? { ...it, status: "error", error: "预览生成超时，请重试" } : it,
+            ),
+          )
+          return
+        }

-        if (status === "completed") {
-          const result: PreviewResult = {
-            taskId: safeString(data.task_id, ""),
-            videoUrl: safeString(data.video_url, ""),
-            clipCount: safeNumber(data.clip_count),
-            transitionCount: safeNumber(data.transition_count),
-            materialUsage: safeNumber(data.material_usage),
-            duration: safeNumber(data.duration),
-            fileSize: safeNumber(data.file_size),
-            generateDuration: safeNumber(data.generate_duration),
-            progress: 100,
+        try {
+          const data: PreviewTaskResponse = await getPreviewStatus(taskId)
+
+          if (taskIdsRef.current.get(index) !== taskId) return
+
+          const status = data.status as ApiPreviewStatus
+
+          if (status === "completed") {
+            const result: PreviewResult = {
+              taskId: safeString(data.task_id, ""),
+              videoUrl: safeString(data.video_url, ""),
+              clipCount: safeNumber(data.clip_count),
+              transitionCount: safeNumber(data.transition_count),
+              materialUsage: safeNumber(data.material_usage),
+              duration: safeNumber(data.duration),
+              fileSize: safeNumber(data.file_size),
+              generateDuration: safeNumber(data.generate_duration),
+              progress: 100,
+            }
+            setItems((prev) =>
+              prev.map((it) =>
+                it.index === index ? { ...it, status: "ready", result, progress: 100 } : it,
+              ),
+            )
+
+            // 保存预览视频 URL 到 plan config，供封面生成使用
+            if (result.videoUrl && selectedTemplate) {
+              updateEditPlan(selectedTemplate, {
+                config: { rendered_storage_key: result.videoUrl },
+              }).catch((err) => {
+                console.warn("[Step4] 保存预览视频URL到plan config失败:", err)
+              })
+            }
+            return
          }
+
+          if (status === "failed") {
+            setItems((prev) =>
+              prev.map((it) =>
+                it.index === index
+                  ? {
+                      ...it,
+                      status: "error",
+                      error: safeString(data.error_message, "预览生成失败，请重试"),
+                    }
+                  : it,
+              ),
+            )
+            return
+          }
+
+          if (status === "cancelled") {
+            setItems((prev) =>
+              prev.map((it) =>
+                it.index === index ? { ...it, status: "error", error: "预览任务已取消" } : it,
+              ),
+            )
+            return
+          }
+
+          // pending / generating 状态继续轮询
+          const prog = safeNumber(data.progress)
+          const nextStatus: PreviewStatus = status === "pending" ? "pending" : "generating"
          setItems((prev) =>
            prev.map((it) =>
-              it.index === index ? { ...it, status: "ready", result, progress: 100 } : it,
+              it.index === index ? { ...it, status: nextStatus, progress: prog } : it,
            ),
          )
-          return
+          const delay = status === "pending" ? 5000 : 2000
+          pollTimersRef.current.set(index, setTimeout(poll, delay))
+        } catch {
+          if (taskIdsRef.current.get(index) !== taskId) return
+          pollTimersRef.current.set(index, setTimeout(poll, 3000))
        }
-
-        if (status === "failed") {
-          setItems((prev) =>
-            prev.map((it) =>
-              it.index === index
-                ? {
-                    ...it,
-                    status: "error",
-                    error: safeString(data.error_message, "预览生成失败，请重试"),
-                  }
-                : it,
-            ),
-          )
-          return
-        }
-
-        if (status === "cancelled") {
-          setItems((prev) =>
-            prev.map((it) =>
-              it.index === index ? { ...it, status: "error", error: "预览任务已取消" } : it,
-            ),
-          )
-          return
-        }
-
-        // pending / generating 状态继续轮询
-        const prog = safeNumber(data.progress)
-        const nextStatus: PreviewStatus = status === "pending" ? "pending" : "generating"
-        setItems((prev) =>
-          prev.map((it) =>
-            it.index === index ? { ...it, status: nextStatus, progress: prog } : it,
-          ),
-        )
-        const delay = status === "pending" ? 5000 : 2000
-        pollTimersRef.current.set(index, setTimeout(poll, delay))
-      } catch {
-        if (taskIdsRef.current.get(index) !== taskId) return
-        pollTimersRef.current.set(index, setTimeout(poll, 3000))
      }
-    }

-    pollTimersRef.current.set(index, setTimeout(poll, 1000))
-  }, [])
+      pollTimersRef.current.set(index, setTimeout(poll, 1000))
+    },
+    [selectedTemplate],
+  )

  /** 生成所有预览 */
  const generatePreview = useCallback(async () => {
@@ -2,7 +2,7 @@
 * Step 6 封面设置 Hook
 * 封装封面设置的交互逻辑，对接后端封面模板 CRUD API
 */
-import { useCallback, useEffect, useRef, useState } from "react"
+import { useCallback, useEffect, useState } from "react"
 import { message } from "antd"
 import type { CoverConfig, CoverTemplate } from "../../editing-planner/types"
 import { generateCover } from "@/api/template-editor"
@@ -30,7 +30,7 @@ export function useStep6Cover({
  assetIds = [],
  selectedTemplate = "",
 }: UseStep6CoverProps) {
-  const generatingRef = useRef(false)
+  const [generating, setGenerating] = useState(false)

  // ── 封面设置弹窗状态 ──
  const [showCoverSettings, setShowCoverSettings] = useState(false)
@@ -67,7 +67,7 @@ export function useStep6Cover({

  /** 调用后端智能封面 API，生成封面并更新预览 */
  const generateAutoCover = useCallback(async () => {
-    if (generatingRef.current) {
+    if (generating) {
      message.warning("封面正在生成中，请稍候...")
      return
    }
@@ -82,12 +82,17 @@ export function useStep6Cover({
      return
    }

-    generatingRef.current = true
+    setGenerating(true)
+    // 超时保护：300 秒后强制重置，防止 state 卡死导致按钮永久失效
+    const timeoutId = setTimeout(() => {
+      setGenerating(false)
+    }, 300000)
    try {
      const response = await generateCover(selectedTemplate, {
        asset_ids: assetIds,
        cover_type: "ai_frame",
      })
+      clearTimeout(timeoutId)
      const thumbnailUrl = response.cover?.image_url || ""
      if (thumbnailUrl) {
        onCoverSettingsChange({
@@ -100,12 +105,35 @@ export function useStep6Cover({
        message.warning("封面生成未返回图片，请重试")
      }
    } catch (err) {
-      console.warn("[Step6] 智能封面生成失败:", err)
-      message.error("封面生成失败，请稍后重试")
+      clearTimeout(timeoutId)
+      console.error("[Step6] 智能封面生成失败:", err)
+
+      // 提取详细错误信息
+      let errorMsg = "封面生成失败"
+      const e = err as {
+        response?: { data?: { detail?: string; message?: string }; status?: number }
+        request?: unknown
+        message?: string
+      }
+      if (e.response) {
+        // 后端返回错误
+        const detail = e.response.data?.detail || e.response.data?.message || ""
+        errorMsg = detail || `后端错误 (${e.response.status})`
+        console.error("[Step6] 后端返回:", e.response.data)
+      } else if (e.request) {
+        // 请求已发送但无响应
+        errorMsg = "服务器无响应，请检查网络连接"
+        console.error("[Step6] 请求无响应:", e.request)
+      } else if (e.message) {
+        errorMsg = e.message
+      }
+
+      message.error(errorMsg)
    } finally {
-      generatingRef.current = false
+      clearTimeout(timeoutId)
+      setGenerating(false)
    }
-  }, [selectedTemplate, assetIds, coverSettings, onCoverSettingsChange])
+  }, [selectedTemplate, assetIds, coverSettings, onCoverSettingsChange, generating])

  // ── 模板操作方法 ──
  const handleSelectTemplate = useCallback((id: string) => {
@@ -165,6 +193,7 @@ export function useStep6Cover({

  return {
    coverSettings,
+    generating,
    generateAutoCover,
    totalDuration,
    showCoverSettings,
@@ -149,7 +149,6 @@ vi.mock("@/api/editing-planner", () => ({
 vi.mock("@/api/template-editor", () => ({
  getMediaAssets: vi.fn().mockResolvedValue({ items: [] }),
  getEditPlanGenerations: vi.fn().mockResolvedValue({ items: [] }),
-  generateCover: vi.fn().mockResolvedValue({}),
  getEditPlan: vi.fn().mockResolvedValue({}),
  createEditPlan: vi.fn().mockResolvedValue({ id: "test-plan" }),
  updateEditPlan: vi.fn().mockResolvedValue({}),
@@ -223,9 +222,6 @@ vi.mock("@/pages/editing-planner/components/GreenScreenPanel", () => ({
 vi.mock("@/pages/editing-planner/components/StickerPanel", () => ({
  default: () => React.createElement("div", { "data-testid": "StickerPanel" }),
 }))
-vi.mock("@/pages/editing-planner/components/CoverSelector", () => ({
-  default: () => React.createElement("div", { "data-testid": "CoverSelector" }),
-}))
 vi.mock("@/pages/editing-planner/components/SaveModal", () => ({
  default: () => React.createElement("div", { "data-testid": "SaveModal" }),
 }))
@@ -260,7 +256,6 @@ vi.mock("@/pages/editing-planner/types", () => ({
  DEFAULT_FILTER_CONFIG: { enabled: false },
  DEFAULT_CHROMA_KEY_CONFIG: { enabled: false },
  DEFAULT_STICKER_CONFIG: { enabled: false },
-  DEFAULT_COVER_CONFIG: { enabled: false },
 }))

 vi.mock("@/pages/editing-planner/types/subtitle", () => ({
@@ -1,24 +0,0 @@
-import { describe, expect, it, vi } from "vitest"
-import { render } from "@testing-library/react"
-import CoverSelector from "@/pages/editing-planner/components/CoverSelector"
-import { DEFAULT_COVER_CONFIG } from "@/pages/editing-planner/types"
-
-const defaultProps = {
-  open: true,
-  onClose: vi.fn(),
-  config: DEFAULT_COVER_CONFIG,
-  onChange: vi.fn(),
-  totalDuration: 60,
-}
-
-describe("CoverSelector", () => {
-  it("should render without crashing", () => {
-    const { container } = render(<CoverSelector {...defaultProps} />)
-    expect(container).toBeTruthy()
-  })
-
-  it("should render when closed", () => {
-    const { container } = render(<CoverSelector {...defaultProps} open={false} />)
-    expect(container).toBeTruthy()
-  })
-})
@@ -6,15 +6,10 @@ const defaultProps = {
  clips: [],
  selectedClipId: null,
  isPlaying: false,
-  currentCoverScheme: "scheme1",
-  coverSchemes: [{ id: "scheme1", name: "方案1", cover_url: "" }],
-  aiCoverLoading: false,
  titleSettings: undefined,
  subtitleSettings: undefined,
  onClipSelect: vi.fn(),
-  onCoverSchemeChange: vi.fn(),
  onPlayPause: vi.fn(),
-  onAiGenerateCover: vi.fn(),
 }

 describe("PreviewPlayer", () => {
@@ -1,5 +1,5 @@
 import { afterEach, describe, expect, it, vi } from "vitest"
-import { render, cleanup } from "@testing-library/react"
+import { render, cleanup, act } from "@testing-library/react"
 import TtsPanel from "@/pages/editing-planner/components/TtsPanel"
 import { DEFAULT_TTS_CONFIG } from "@/pages/editing-planner/types"

@@ -16,17 +16,28 @@ const defaultProps = {
 }

 describe("TtsPanel", () => {
-  afterEach(() => {
+  afterEach(async () => {
+    // Flush pending React updates before cleanup to avoid
+    // "window is not defined" errors after jsdom teardown
+    await act(async () => {})
    cleanup()
  })

-  it("should render without crashing", () => {
-    const { container } = render(<TtsPanel {...defaultProps} />)
-    expect(container).toBeTruthy()
+  it("should render without crashing", async () => {
+    let container: HTMLElement
+    await act(async () => {
+      const result = render(<TtsPanel {...defaultProps} />)
+      container = result.container
+    })
+    expect(container!).toBeTruthy()
  })

-  it("should render when closed", () => {
-    const { container } = render(<TtsPanel {...defaultProps} open={false} />)
-    expect(container).toBeTruthy()
+  it("should render when closed", async () => {
+    let container: HTMLElement
+    await act(async () => {
+      const result = render(<TtsPanel {...defaultProps} open={false} />)
+      container = result.container
+    })
+    expect(container!).toBeTruthy()
  })
 })
@@ -28,7 +28,6 @@ import "@/pages/editing-planner/utils/clipProperties"
 // 子组件
 import "@/pages/editing-planner/components/BgmSelector"
 import "@/pages/editing-planner/components/ClipPropertiesPanel"
-import "@/pages/editing-planner/components/CoverSelector"
 import "@/pages/editing-planner/components/EditorClipList"
 import "@/pages/editing-planner/components/EditingDrawers"
 import "@/pages/editing-planner/components/FilterPanel"
@@ -1436,6 +1436,64 @@ def generate_video(self, task_id: str) -> dict:

            _update_task_progress(task_id, 30, "素材下载完成")

+            # ── 2.5 MediaKit 视频理解（渲染前分析素材内容）─────────────────
+            asset_analyses = {}
+            if task_asset_ids:
+                try:
+                    from packages.shared.mediakit_client import get_mediakit_client
+                    from packages.shared.storage import get_shared_storage_service
+
+                    mk_client = get_mediakit_client()
+                    if mk_client.is_available:
+                        storage_svc = get_shared_storage_service()
+                        asset_urls = []
+                        valid_asset_ids = []
+
+                        # 获取素材 URL（从 downloaded_videos 获取本地路径或从 asset 表获取 OSS URL）
+                        for i, asset_id in enumerate(task_asset_ids[:5]):
+                            try:
+                                # 优先使用已下载的本地文件
+                                if i < len(downloaded_videos) and downloaded_videos[i]:
+                                    # 本地文件路径，需要上传或直接用 OSS URL
+                                    from packages.adapters.sqlalchemy_impl.asset_repository import (
+                                        SQLAlchemyAssetRepository,
+                                    )
+
+                                    _s = SessionLocal()
+                                    try:
+                                        _ar = SQLAlchemyAssetRepository(_s)
+                                        asset = _ar.get(asset_id)
+                                        if asset and getattr(asset, "storage_key", ""):
+                                            asset_urls.append(storage_svc.get_url(asset.storage_key))
+                                            valid_asset_ids.append(asset_id)
+                                    finally:
+                                        _s.close()
+                            except Exception:
+                                continue
+
+                        if asset_urls:
+                            _update_task_progress(task_id, 35, "MediaKit 视频理解中...")
+                            analyses = mk_client.analyze_videos(
+                                prompt="分析这个视频的主要内容，描述场景、物体、人物动作和主题",
+                                video_urls=asset_urls,
+                                level="Economy",
+                                poll_interval=2.0,
+                                max_poll_attempts=15,
+                            )
+                            if analyses:
+                                for i, content in enumerate(analyses):
+                                    if i < len(valid_asset_ids) and content:
+                                        asset_analyses[valid_asset_ids[i]] = content
+                            logger.info("[task_id=%s] MediaKit 视频理解完成: %d 个素材", task_id, len(asset_urls))
+
+                    # 保存分析结果到 extra_meta
+                    if asset_analyses and gen_task:
+                        gen_task.extra_meta = {**(gen_task.extra_meta or {}), "asset_analyses": asset_analyses}
+                        _repo.update(gen_task)
+                        _flush_logs(task_id, gen_task)
+                except Exception:
+                    logger.warning("[task_id=%s] MediaKit 视频理解失败，继续渲染", task_id, exc_info=True)
+
            # ── 3. 渲染 + 混音 ───────────────────────────────────────────────
            _update_task_progress(task_id, 40, "开始渲染")
            # 动态分辨率：优先使用 output_width/output_height，其次 resolution 字符串
@@ -148,6 +148,22 @@ class SQLAlchemyGenerationTaskRepository:
        )
        return [_to_domain(m) for m in models]

+    def list_latest_completed_preview(self, user_id: str, template_id: str, limit: int = 1) -> list[GenerationTask]:
+        """按用户+模板查找最近已完成的预览任务。"""
+        models = (
+            self.session.query(GenerationTaskModel)
+            .filter(
+                GenerationTaskModel.created_by_user_id == user_id,
+                GenerationTaskModel.template_id == template_id,
+                GenerationTaskModel.is_preview,
+                GenerationTaskModel.status == "completed",
+            )
+            .order_by(GenerationTaskModel.created_at.desc())
+            .limit(limit)
+            .all()
+        )
+        return [_to_domain(m) for m in models]
+
    def list_by_source_edit_plan(self, plan_id: str) -> list[GenerationTask]:
        models = (
            self.session.query(GenerationTaskModel)
@@ -362,7 +362,7 @@ def _call_ai_cover_service(
    """调用 AI 封面生成服务.

    当 cover_type 为 ai_frame 或 ai_regenerate 时，调用 MediaKit 视频截帧。
-    失败或未配置时降级为 stub 行为。
+    失败时抛出 RuntimeError。

    Args:
        plan_id: 剪辑计划 ID
@@ -402,8 +402,10 @@ def _call_ai_cover_service(
                logger.info("调用 MediaKit 抽帧: plan_id=%s video=%s", plan_id, primary_video_url[:80])
                frames = client.extract_frames(
                    video_url=primary_video_url,
-                    strategy="TimeInterval",
-                    max_frames=5,
+                    strategy="SceneChange",  # 自动识别画面变化，选最佳帧
+                    max_frames=3,  # 减少到 3 帧，平衡速度和质量
+                    poll_interval=2.0,  # 缩短轮询间隔
+                    max_poll_attempts=60,  # 120秒超时
                )

                if frames and len(frames) > 0:
@@ -432,25 +434,12 @@ def _call_ai_cover_service(
                        logger.warning("MediaKit 返回的帧无 image_url")

            except Exception as e:
-                logger.exception("MediaKit 抽帧失败，降级到 stub: %s", str(e))
+                logger.exception("MediaKit 抽帧失败: %s", str(e))

-    # 降级：stub 行为 - 返回 SVG data URI 占位图
-    logger.info("使用 stub 封面: plan_id=%s", plan_id)
-    time.sleep(0.3)
-    svg_placeholder = (
-        "data:image/svg+xml,"
-        "<svg xmlns='http://www.w3.org/2000/svg' width='1080' height='1920'>"
-        "<rect width='1080' height='1920' fill='#1a1a2e'/>"
-        "<text x='540' y='920' text-anchor='middle' fill='#e0e0e0' font-size='48' font-family='sans-serif'>封面生成中</text>"
-        "<text x='540' y='1000' text-anchor='middle' fill='#888888' font-size='32' font-family='sans-serif'>请配置 MediaKit API Key</text>"
-        "</svg>"
+    # 封面生成失败 - 不再降级到 stub，直接报错
+    raise RuntimeError(
+        f"封面生成失败: plan_id={plan_id}, MediaKit 不可用或抽帧失败。" f"请检查 primary_video_url 是否可访问。"
    )
-    return {
-        "type": "ai_frame",
-        "image_url": svg_placeholder,
-        "frame_time": round(random.uniform(1.0, 10.0), 1),
-        "confidence": round(random.uniform(0.80, 0.98), 2),
-    }


 # ── 公共入口 ────────────────────────────────────────────────────────────────
@@ -399,18 +399,16 @@ class TestRunAIRecommend(unittest.TestCase):


 class TestGenerateCover(unittest.TestCase):
-    """封面生成测试（降级路径）."""
+    """封面生成测试."""

-    def test_ai_frame_type(self):
-        """AI封面模式返回预期结构."""
-        result = run_generate_cover(
-            plan_id="plan-1",
-            asset_ids=["a1"],
-            cover_type="ai_frame",
-        )
-        self.assertIn("type", result)
-        self.assertEqual(result["type"], "ai_frame")
-        self.assertIn("image_url", result)
+    def test_ai_frame_type_raises_without_mediakit(self):
+        """AI封面模式在MediaKit不可用时抛出RuntimeError."""
+        with self.assertRaises(RuntimeError):
+            run_generate_cover(
+                plan_id="plan-1",
+                asset_ids=["a1"],
+                cover_type="ai_frame",
+            )

    def test_manual_type(self):
        """手动选帧模式."""
@@ -231,18 +231,18 @@ class TestAIRunTasks:
        # 即使没有素材，也应该有 intro + outro
        assert len(result["clips"]) >= 2

-    def test_run_generate_cover_ai_frame(self):
+    def test_run_generate_cover_ai_frame_raises_without_mediakit(self):
+        """ai_frame cover raises RuntimeError when MediaKit is unavailable."""
+        import pytest
+
        from apps.worker.worker_app.tasks.ai_tasks import run_generate_cover

-        result = run_generate_cover(
-            plan_id="plan-001",
-            asset_ids=["asset-1"],
-            cover_type="ai_frame",
-        )
-        assert result["type"] == "ai_frame"
-        assert "image_url" in result
-        assert "frame_time" in result
-        assert "confidence" in result
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            run_generate_cover(
+                plan_id="plan-001",
+                asset_ids=["asset-1"],
+                cover_type="ai_frame",
+            )

    def test_run_generate_cover_manual(self):
        from apps.worker.worker_app.tasks.ai_tasks import run_generate_cover
@@ -1,400 +0,0 @@
-"""
-封面管理服务单元测试
-"""
-
-import subprocess
-from pathlib import Path
-from unittest.mock import Mock, patch
-
-import pytest
-
-from apps.api.app.services.cover_service import (
-    COVER_STORAGE_PREFIX,
-    DEFAULT_COVER_HEIGHT,
-    DEFAULT_COVER_QUALITY,
-    DEFAULT_COVER_WIDTH,
-    CoverService,
-)
-
-
-class TestGetCoverConfig:
-    """get_cover_config 静态方法测试"""
-
-    def test_get_cover_config_default(self):
-        """测试默认封面配置"""
-        config = {}
-        result = CoverService.get_cover_config(config)
-        assert result["type"] == "ai_frame"
-        assert result["image_url"] == ""
-        assert result["frame_time"] is None
-
-    def test_get_cover_config_with_custom_values(self):
-        """测试自定义封面配置"""
-        config = {
-            "cover": {
-                "type": "manual",
-                "image_url": "https://example.com/cover.jpg",
-                "frame_time": 5.5,
-            }
-        }
-        result = CoverService.get_cover_config(config)
-        assert result["type"] == "manual"
-        assert result["image_url"] == "https://example.com/cover.jpg"
-        assert result["frame_time"] == 5.5
-
-    def test_get_cover_config_cover_not_dict(self):
-        """测试 cover 不是 dict 时返回默认值"""
-        config = {"cover": "not-a-dict"}
-        result = CoverService.get_cover_config(config)
-        assert result["type"] == "ai_frame"
-        assert result["image_url"] == ""
-        assert result["frame_time"] is None
-
-    def test_get_cover_config_partial_fields(self):
-        """测试部分字段存在时，其余字段用默认值"""
-        config = {"cover": {"type": "custom"}}
-        result = CoverService.get_cover_config(config)
-        assert result["type"] == "custom"
-        assert result["image_url"] == ""
-        assert result["frame_time"] is None
-
-    def test_get_cover_config_empty_cover_dict(self):
-        """测试空的 cover dict"""
-        config = {"cover": {}}
-        result = CoverService.get_cover_config(config)
-        assert result["type"] == "ai_frame"
-        assert result["image_url"] == ""
-
-
-class TestExtractCoverFromClip:
-    """extract_cover_from_clip 测试"""
-
-    @pytest.fixture
-    def mock_storage(self):
-        storage = Mock()
-        storage.download_file = Mock()
-        storage.upload_file = Mock()
-        storage.get_url = Mock(return_value="https://oss.example.com/covers/plan1/cover_1000.jpg")
-        return storage
-
-    @pytest.fixture
-    def mock_asset_repo(self):
-        repo = Mock()
-        repo.get = Mock(return_value=None)
-        return repo
-
-    @pytest.fixture
-    def video_asset(self):
-        asset = Mock()
-        asset.storage_key = "videos/test-video.mp4"
-        asset.mime_type = "video/mp4"
-        return asset
-
-    @pytest.fixture
-    def service(self, mock_storage, mock_asset_repo):
-        return CoverService(storage_service=mock_storage, asset_repository=mock_asset_repo)
-
-    def test_extract_cover_asset_not_found(self, service, mock_asset_repo):
-        """测试素材不存在时报错"""
-        mock_asset_repo.get.return_value = None
-
-        with pytest.raises(ValueError, match="素材不存在"):
-            service.extract_cover_from_clip(plan_id="plan-1", asset_id="nonexistent")
-
-    def test_extract_cover_asset_no_storage_key(self, service, mock_asset_repo):
-        """测试素材没有文件时报错"""
-        asset = Mock()
-        asset.storage_key = ""
-        asset.mime_type = "video/mp4"
-        mock_asset_repo.get.return_value = asset
-
-        with pytest.raises(ValueError, match="素材没有文件"):
-            service.extract_cover_from_clip(plan_id="plan-1", asset_id="asset-no-file")
-
-    def test_extract_cover_asset_not_video(self, service, mock_asset_repo):
-        """测试非视频素材报错"""
-        asset = Mock()
-        asset.storage_key = "images/photo.jpg"
-        asset.mime_type = "image/jpeg"
-        mock_asset_repo.get.return_value = asset
-
-        with pytest.raises(ValueError, match="素材不是视频类型"):
-            service.extract_cover_from_clip(plan_id="plan-1", asset_id="asset-img")
-
-    def test_extract_cover_download_failure(self, service, mock_asset_repo, mock_storage, video_asset):
-        """测试下载素材失败"""
-        mock_asset_repo.get.return_value = video_asset
-        mock_storage.download_file.side_effect = Exception("网络错误")
-
-        with pytest.raises(RuntimeError, match="下载素材失败"):
-            service.extract_cover_from_clip(plan_id="plan-1", asset_id="asset-1")
-
-    def test_extract_cover_upload_failure(self, service, mock_asset_repo, mock_storage, video_asset):
-        """测试上传封面失败"""
-        mock_asset_repo.get.return_value = video_asset
-
-        def fake_download(storage_key, local_path):
-            # 创建一个假的视频文件
-            Path(local_path).parent.mkdir(parents=True, exist_ok=True)
-            with open(local_path, "wb") as f:
-                f.write(b"fake video data")
-
-        mock_storage.download_file.side_effect = fake_download
-        mock_storage.upload_file.side_effect = Exception("上传失败")
-
-        # mock _extract_frame 避免真的调 ffmpeg
-        with patch.object(CoverService, "_extract_frame") as mock_extract:
-
-            def fake_extract(video_path, output_path, **kwargs):
-                # 创建假的封面文件
-                with open(output_path, "wb") as f:
-                    f.write(b"\xff\xd8\xff\xe0fake jpeg data")
-
-            mock_extract.side_effect = fake_extract
-
-            with pytest.raises(RuntimeError, match="上传封面失败"):
-                service.extract_cover_from_clip(plan_id="plan-1", asset_id="asset-1")
-
-    def test_extract_cover_get_url_falls_back_to_key(self, service, mock_asset_repo, mock_storage, video_asset):
-        """测试获取 URL 失败时降级为 storage_key"""
-        mock_asset_repo.get.return_value = video_asset
-
-        def fake_download(storage_key, local_path):
-            Path(local_path).parent.mkdir(parents=True, exist_ok=True)
-            with open(local_path, "wb") as f:
-                f.write(b"fake video data")
-
-        mock_storage.download_file.side_effect = fake_download
-        mock_storage.get_url.side_effect = Exception("URL服务不可用")
-
-        with patch.object(CoverService, "_extract_frame") as mock_extract:
-
-            def fake_extract(video_path, output_path, **kwargs):
-                with open(output_path, "wb") as f:
-                    f.write(b"\xff\xd8\xff\xe0fake jpeg")
-
-            mock_extract.side_effect = fake_extract
-
-            result = service.extract_cover_from_clip(plan_id="plan-abc", asset_id="asset-xyz", frame_time=2.5)
-
-        assert result["type"] == "manual"
-        assert result["frame_time"] == 2.5
-        # URL 失败时返回 storage_key
-        assert COVER_STORAGE_PREFIX in result["image_url"]
-        assert "plan-abc" in result["image_url"]
-
-    def test_extract_cover_success(self, service, mock_asset_repo, mock_storage, video_asset):
-        """测试抽帧成功完整流程"""
-        mock_asset_repo.get.return_value = video_asset
-
-        def fake_download(storage_key, local_path):
-            Path(local_path).parent.mkdir(parents=True, exist_ok=True)
-            with open(local_path, "wb") as f:
-                f.write(b"fake video data for testing")
-
-        mock_storage.download_file.side_effect = fake_download
-
-        with patch.object(CoverService, "_extract_frame") as mock_extract:
-
-            def fake_extract(video_path, output_path, **kwargs):
-                with open(output_path, "wb") as f:
-                    f.write(b"\xff\xd8\xff\xe0fake jpeg image data")
-
-            mock_extract.side_effect = fake_extract
-
-            result = service.extract_cover_from_clip(
-                plan_id="plan-123",
-                asset_id="asset-456",
-                frame_time=3.0,
-                width=720,
-                height=1280,
-                quality=3,
-            )
-
-        assert result["type"] == "manual"
-        assert result["image_url"] == "https://oss.example.com/covers/plan1/cover_1000.jpg"
-        assert result["frame_time"] == 3.0
-
-        # 验证上传被调用
-        mock_storage.upload_file.assert_called_once()
-        upload_args = mock_storage.upload_file.call_args[1]
-        assert upload_args["content_type"] == "image/jpeg"
-        assert "plan-123" in upload_args["storage_key"]
-        assert "3000" in upload_args["storage_key"]  # frame_time * 1000
-
-        # 验证 _extract_frame 被调用且参数正确
-        mock_extract.assert_called_once()
-        extract_kwargs = mock_extract.call_args[1]
-        assert extract_kwargs["time_sec"] == 3.0
-        assert extract_kwargs["width"] == 720
-        assert extract_kwargs["height"] == 1280
-        assert extract_kwargs["quality"] == 3
-
-
-class TestGenerateSmartCover:
-    """generate_smart_cover 测试"""
-
-    @pytest.fixture
-    def service(self):
-        return CoverService(storage_service=Mock(), asset_repository=Mock())
-
-    def test_generate_smart_cover_calls_extract_with_default_time(self, service):
-        """测试智能封面调用 extract_cover_from_clip 并设置 type 为 ai_frame"""
-        fake_result = {"type": "manual", "image_url": "test.jpg", "frame_time": 3.0}
-
-        with patch.object(service, "extract_cover_from_clip", return_value=fake_result) as mock_extract:
-            result = service.generate_smart_cover(plan_id="plan-1", asset_id="asset-1")
-
-            mock_extract.assert_called_once()
-            call_kwargs = mock_extract.call_args[1]
-            assert call_kwargs["plan_id"] == "plan-1"
-            assert call_kwargs["asset_id"] == "asset-1"
-            assert call_kwargs["frame_time"] == 3.0  # 默认第3秒
-
-        assert result["type"] == "ai_frame"
-        assert result["image_url"] == "test.jpg"
-
-    def test_generate_smart_cover_passes_dimensions(self, service):
-        """测试智能封面传递尺寸和质量参数"""
-        fake_result = {"type": "manual", "image_url": "test.jpg", "frame_time": 3.0}
-
-        with patch.object(service, "extract_cover_from_clip", return_value=fake_result) as mock_extract:
-            service.generate_smart_cover(
-                plan_id="plan-1",
-                asset_id="asset-1",
-                width=1080,
-                height=1920,
-                quality=5,
-            )
-
-            call_kwargs = mock_extract.call_args[1]
-            assert call_kwargs["width"] == 1080
-            assert call_kwargs["height"] == 1920
-            assert call_kwargs["quality"] == 5
-
-
-class TestExtractFrame:
-    """_extract_frame 静态方法测试（mock subprocess）"""
-
-    @pytest.fixture
-    def video_path(self, tmp_path):
-        path = tmp_path / "test_video.mp4"
-        path.write_bytes(b"fake video")
-        return path
-
-    @pytest.fixture
-    def output_path(self, tmp_path):
-        return tmp_path / "cover.jpg"
-
-    def test_extract_frame_success(self, video_path, output_path):
-        """测试 FFmpeg 抽帧成功"""
-        fake_result = Mock()
-        fake_result.returncode = 0
-
-        with patch("subprocess.run", return_value=fake_result) as mock_run:
-            CoverService._extract_frame(
-                video_path=video_path,
-                output_path=output_path,
-                time_sec=2.5,
-                width=1080,
-                height=1920,
-                quality=5,
-            )
-
-            assert mock_run.call_count == 1
-            cmd = mock_run.call_args[0][0]
-            assert cmd[0] == "ffmpeg"
-            assert "-ss" in cmd
-            assert "2.500" in cmd
-            assert "-vframes" in cmd
-            # 验证 scale+crop 滤镜存在
-            vf_index = cmd.index("-vf") + 1
-            assert "scale=" in cmd[vf_index]
-            assert "crop=" in cmd[vf_index]
-
-    def test_extract_frame_fallback_to_simple_command(self, video_path, output_path):
-        """测试主命令失败时回退到简化命令"""
-        fail_result = Mock()
-        fail_result.returncode = 1
-        fail_result.stderr = "Filter graph error"
-
-        success_result = Mock()
-        success_result.returncode = 0
-
-        call_count = 0
-
-        def fake_run(*args, **kwargs):
-            nonlocal call_count
-            call_count += 1
-            if call_count == 1:
-                return fail_result
-            return success_result
-
-        with patch("subprocess.run", side_effect=fake_run) as mock_run:
-            CoverService._extract_frame(
-                video_path=video_path,
-                output_path=output_path,
-                time_sec=1.0,
-                width=1080,
-                height=1920,
-                quality=5,
-            )
-
-            assert mock_run.call_count == 2
-            # 第二次是简化命令（没有 -vf 参数）
-            second_cmd = mock_run.call_args_list[1][0][0]
-            assert "-vf" not in second_cmd
-
-    def test_extract_frame_both_commands_fail(self, video_path, output_path):
-        """测试两个命令都失败时报错"""
-        fail_result = Mock()
-        fail_result.returncode = 1
-        fail_result.stderr = "Invalid data found when processing input"
-
-        with patch("subprocess.run", return_value=fail_result):
-            with pytest.raises(RuntimeError, match="FFmpeg 抽帧失败"):
-                CoverService._extract_frame(
-                    video_path=video_path,
-                    output_path=output_path,
-                    time_sec=1.0,
-                    width=1080,
-                    height=1920,
-                    quality=5,
-                )
-
-    def test_extract_frame_timeout(self, video_path, output_path):
-        """测试 FFmpeg 抽帧超时"""
-        with patch("subprocess.run", side_effect=subprocess.TimeoutExpired(cmd="ffmpeg", timeout=60)):
-            with pytest.raises(RuntimeError, match="FFmpeg 抽帧超时"):
-                CoverService._extract_frame(
-                    video_path=video_path,
-                    output_path=output_path,
-                    time_sec=1.0,
-                    width=1080,
-                    height=1920,
-                    quality=5,
-                )
-
-    def test_extract_frame_ffmpeg_not_found(self, video_path, output_path):
-        """测试 FFmpeg 不可用"""
-        with patch("subprocess.run", side_effect=FileNotFoundError("ffmpeg not found")):
-            with pytest.raises(RuntimeError, match="FFmpeg 不可用"):
-                CoverService._extract_frame(
-                    video_path=video_path,
-                    output_path=output_path,
-                    time_sec=1.0,
-                    width=1080,
-                    height=1920,
-                    quality=5,
-                )
-
-
-class TestDefaults:
-    """默认常量测试"""
-
-    def test_default_dimensions(self):
-        """测试默认尺寸常量"""
-        assert DEFAULT_COVER_WIDTH == 1080
-        assert DEFAULT_COVER_HEIGHT == 1920
-        assert DEFAULT_COVER_QUALITY == 5
-        assert COVER_STORAGE_PREFIX == "covers"
@@ -630,7 +630,7 @@ class TestToPreviewResponse:
        assert resp.file_size == 0

    def test_completed_task_with_videos(self):
-        """已完成任务，带视频结果（URL签名后返回）"""
+        """已完成任务，带视频结果（裸URL直接返回，rendered/*已公开读）"""
        task = _make_task(
            status=GenerationTaskStatus.COMPLETED,
            progress=100.0,
@@ -639,12 +639,8 @@ class TestToPreviewResponse:
        video.file_url = "https://cdn.example.com/preview.mp4"
        video.duration = 30.5
        video.file_size = 1024000
-        # Mock storage service to return a signed URL
-        mock_storage = MagicMock()
-        mock_storage.get_download_url.return_value = "https://cdn.example.com/preview.mp4?sig=test123"
-        with patch("app.api.routes.generation_preview.get_storage_service", return_value=mock_storage):
-            resp = _to_preview_response(task, generated_videos=[video])
-        assert resp.video_url == "https://cdn.example.com/preview.mp4?sig=test123"
+        resp = _to_preview_response(task, generated_videos=[video])
+        assert resp.video_url == "https://cdn.example.com/preview.mp4"
        assert resp.duration == 30.5
        assert resp.file_size == 1024000

@@ -986,7 +982,7 @@ class TestGetPreviewRoute:

        # Mock URL 签名（返回带签名的 URL）
        mock_storage = MagicMock()
-        mock_storage.get_download_url.return_value = "https://cdn.example.com/preview_final.mp4?sig=abc123"
+        mock_storage.get_download_url.return_value = "https://cdn.example.com/preview_final.mp4"

        with patch("app.api.routes.generation_preview.GetGenerationTaskUseCase") as MockGet:
            MockGet.return_value.execute.return_value = task
@@ -999,7 +995,7 @@ class TestGetPreviewRoute:
                        generation_task_repository=repo,
                        generated_video_repository=vid_repo,
                    )
-        assert resp.video_url == "https://cdn.example.com/preview_final.mp4?sig=abc123"
+        assert resp.video_url == "https://cdn.example.com/preview_final.mp4"
        assert resp.duration == 25.0


@@ -1088,50 +1084,6 @@ class TestWorkerPreviewResolution:
 # ═══════════════════════════════════════════════════════════════════════════════


-class TestSignVideoUrl:
-    """_sign_video_url 预签名 URL 测试。"""
-
-    def test_empty_url_returns_empty(self):
-        """空 URL 直接返回空字符串。"""
-        from app.api.routes.generation_preview import _sign_video_url
-
-        assert _sign_video_url("") == ""
-
-    def test_signs_oss_url(self):
-        """OSS URL 应被签名。"""
-        from app.api.routes.generation_preview import _sign_video_url
-
-        mock_storage = MagicMock()
-        mock_storage.get_download_url.return_value = "https://signed.example.com/video.mp4?sig=abc"
-
-        with patch("app.api.routes.generation_preview.get_storage_service", return_value=mock_storage):
-            result = _sign_video_url("https://bucket.oss.example.com/video.mp4")
-
-        assert result == "https://signed.example.com/video.mp4?sig=abc"
-        mock_storage.get_download_url.assert_called_once()
-
-    def test_fallback_on_sign_failure(self):
-        """签名失败时降级返回原始 URL。"""
-        from app.api.routes.generation_preview import _sign_video_url
-
-        with patch("app.api.routes.generation_preview.get_storage_service", side_effect=RuntimeError("no storage")):
-            result = _sign_video_url("https://bucket.oss.example.com/video.mp4")
-
-        assert result == "https://bucket.oss.example.com/video.mp4"
-
-    def test_sign_returns_none_fallback(self):
-        """get_download_url 返回 None 时降级返回原始 URL。"""
-        from app.api.routes.generation_preview import _sign_video_url
-
-        mock_storage = MagicMock()
-        mock_storage.get_download_url.return_value = None
-
-        with patch("app.api.routes.generation_preview.get_storage_service", return_value=mock_storage):
-            result = _sign_video_url("https://bucket.oss.example.com/video.mp4")
-
-        assert result == "https://bucket.oss.example.com/video.mp4"
-
-
 class TestInferVideoRatioFromTemplate:
    """_infer_video_ratio_from_template 单元测试。"""

@@ -167,8 +167,8 @@ class TestAICoverService:
        mock_client.extract_frames.assert_called_once()

    @patch("packages.shared.mediakit_client.get_mediakit_client")
-    def test_call_ai_cover_with_mediakit_failure_fallback(self, mock_get_client):
-        """MediaKit 失败时降级到 stub."""
+    def test_call_ai_cover_with_mediakit_failure_raises(self, mock_get_client):
+        """MediaKit 失败时抛出 RuntimeError（不再降级到 stub）."""
        mock_client = Mock()
        mock_client.is_available = True
        mock_client.extract_frames.side_effect = Exception("API error")
@@ -176,30 +176,26 @@ class TestAICoverService:

        from packages.shared.ai_service import _call_ai_cover_service

-        result = _call_ai_cover_service(
-            plan_id="plan-123",
-            asset_ids=["asset-1"],
-            cover_type="ai_frame",
-            primary_video_url="https://example.com/video.mp4",
-        )
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service(
+                plan_id="plan-123",
+                asset_ids=["asset-1"],
+                cover_type="ai_frame",
+                primary_video_url="https://example.com/video.mp4",
+            )

-        # 应该降级到 stub
-        assert result["type"] == "ai_frame"
-        assert result["image_url"].startswith("data:image/svg+xml,")
+    def test_call_ai_cover_without_video_url_raises(self):
+        """没有视频 URL 时抛出 RuntimeError（不再降级到 stub）."""

-    def test_call_ai_cover_without_video_url_fallback(self):
-        """没有视频 URL 时使用 stub."""
        from packages.shared.ai_service import _call_ai_cover_service

-        result = _call_ai_cover_service(
-            plan_id="plan-123",
-            asset_ids=["asset-1"],
-            cover_type="ai_frame",
-            primary_video_url=None,
-        )
-
-        assert result["type"] == "ai_frame"
-        assert result["image_url"].startswith("data:image/svg+xml,")
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service(
+                plan_id="plan-123",
+                asset_ids=["asset-1"],
+                cover_type="ai_frame",
+                primary_video_url=None,
+            )

    def test_call_ai_cover_upload_type(self):
        """upload 类型直接返回."""
@@ -231,27 +227,25 @@ class TestAICoverService:
        assert result["frame_time"] == 5.0

    @patch("packages.shared.mediakit_client.get_mediakit_client")
-    def test_call_ai_cover_mediakit_not_available(self, mock_get_client):
-        """MediaKit 未配置时使用 stub."""
+    def test_call_ai_cover_mediakit_not_available_raises(self, mock_get_client):
+        """MediaKit 未配置时抛出 RuntimeError（不再降级到 stub）."""
        mock_client = Mock()
        mock_client.is_available = False
        mock_get_client.return_value = mock_client

        from packages.shared.ai_service import _call_ai_cover_service

-        result = _call_ai_cover_service(
-            plan_id="plan-123",
-            asset_ids=["asset-1"],
-            cover_type="ai_frame",
-            primary_video_url="https://example.com/video.mp4",
-        )
-
-        assert result["type"] == "ai_frame"
-        assert result["image_url"].startswith("data:image/svg+xml,")
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service(
+                plan_id="plan-123",
+                asset_ids=["asset-1"],
+                cover_type="ai_frame",
+                primary_video_url="https://example.com/video.mp4",
+            )

    @patch("packages.shared.mediakit_client.get_mediakit_client")
-    def test_call_ai_cover_empty_frames_fallback(self, mock_get_client):
-        """MediaKit 返回空帧列表时降级."""
+    def test_call_ai_cover_empty_frames_raises(self, mock_get_client):
+        """MediaKit 返回空帧列表时抛出 RuntimeError（不再降级）."""
        mock_client = Mock()
        mock_client.is_available = True
        mock_client.extract_frames.return_value = []
@@ -259,15 +253,13 @@ class TestAICoverService:

        from packages.shared.ai_service import _call_ai_cover_service

-        result = _call_ai_cover_service(
-            plan_id="plan-123",
-            asset_ids=["asset-1"],
-            cover_type="ai_frame",
-            primary_video_url="https://example.com/video.mp4",
-        )
-
-        assert result["type"] == "ai_frame"
-        assert result["image_url"].startswith("data:image/svg+xml,")
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service(
+                plan_id="plan-123",
+                asset_ids=["asset-1"],
+                cover_type="ai_frame",
+                primary_video_url="https://example.com/video.mp4",
+            )


 class TestGenerateCover:
@@ -434,34 +434,22 @@ class TestAiCoverService:
        assert result["image_url"].startswith("data:image/svg+xml,")
        assert "手动选帧" in result["image_url"]

-    def test_cover_type_ai_frame(self):
-        with patch("shared.ai_service.time.sleep"):
-            with patch("shared.ai_service.random.uniform", side_effect=[5.0, 0.9]):
-                result = _call_ai_cover_service("plan1", ["a1"], "ai_frame")
-        assert result["type"] == "ai_frame"
-        assert result["frame_time"] == 5.0
-        assert result["confidence"] == 0.9
-        assert result["image_url"].startswith("data:image/svg+xml,")
-        assert "封面生成中" in result["image_url"]
+    def test_cover_type_ai_frame_raises_without_mediakit(self):
+        """ai_frame mode raises RuntimeError when MediaKit is unavailable."""
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service("plan1", ["a1"], "ai_frame")

-    def test_cover_type_ai_regenerate(self):
-        with patch("shared.ai_service.time.sleep"):
-            result = _call_ai_cover_service("plan1", ["a1"], "ai_regenerate")
-        assert result["type"] == "ai_frame"
+    def test_cover_type_ai_regenerate_raises_without_mediakit(self):
+        """ai_regenerate mode raises RuntimeError when MediaKit is unavailable."""
+        with pytest.raises(RuntimeError, match="MediaKit"):
+            _call_ai_cover_service("plan1", ["a1"], "ai_regenerate")

-    def test_cover_frame_time_in_range(self):
+    def test_cover_type_manual_still_works(self):
+        """manual mode does not require MediaKit and still returns stub."""
        with patch("shared.ai_service.time.sleep"):
-            result = _call_ai_cover_service("plan1", ["a1"], "ai_frame")
-        assert 1.0 <= result["frame_time"] <= 10.0
-
-    def test_stub_returns_svg_data_uri(self):
-        """stub 降级返回 SVG data URI，不含任何后端 API 路径."""
-        with patch("shared.ai_service.time.sleep"):
-            result = _call_ai_cover_service("plan1", ["a1"], "ai_frame")
-        assert result["image_url"].startswith("data:image/svg+xml,")
-        assert "/api/v1/" not in result["image_url"]
-        assert "1080" in result["image_url"]
-        assert "1920" in result["image_url"]
+            result = _call_ai_cover_service("plan1", ["a1"], "manual", frame_time=5.5)
+        assert result["type"] == "manual"
+        assert result["frame_time"] == 5.5

    def test_manual_stub_returns_svg_data_uri(self):
        """manual 模式返回 SVG data URI 占位图."""