添加视频帧提取功能和阿里云OSS存储支持

- 新增从视频素材提取首帧/尾帧的功能，支持画面连续性编辑
- 添加阿里云OSS存储支持，可配置本地或OSS存储方式
- 导入视频素材时自动探测并更新视频时长信息
- 前端添加从素材提取尾帧的UI界面
- 添加FramePrompt模型的数据库迁移

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

api/handlers/asset.go

@@ -20,7 +20,7 @@ type AssetHandler struct {
 
 func NewAssetHandler(db *gorm.DB, cfg *config.Config, log *logger.Logger) *AssetHandler {
 	return &AssetHandler{
-		assetService: services.NewAssetService(db, log),
+		assetService: services.NewAssetService(db, log, cfg),
 		log:          log,
 	}
 }
@@ -218,3 +218,27 @@ func (h *AssetHandler) ImportFromVideoGen(c *gin.Context) {
 
 	response.Success(c, asset)
 }
+
+// ExtractFrame 从视频素材中提取帧
+func (h *AssetHandler) ExtractFrame(c *gin.Context) {
+	assetID, err := strconv.ParseUint(c.Param("id"), 10, 32)
+	if err != nil {
+		response.BadRequest(c, "无效的ID")
+		return
+	}
+
+	var req services.ExtractFrameRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+
+	imageGen, err := h.assetService.ExtractFrameFromAsset(uint(assetID), &req)
+	if err != nil {
+		h.log.Errorw("Failed to extract frame", "error", err, "asset_id", assetID)
+		response.InternalError(c, err.Error())
+		return
+	}
+
+	response.Success(c, imageGen)
+}

api/routes/routes.go

@@ -180,6 +180,7 @@ func SetupRouter(cfg *config.Config, db *gorm.DB, log *logger.Logger, localStora
 			assets.DELETE("/:id", assetHandler.DeleteAsset)
 			assets.POST("/import/image/:image_gen_id", assetHandler.ImportFromImageGen)
 			assets.POST("/import/video/:video_gen_id", assetHandler.ImportFromVideoGen)
+			assets.POST("/:id/extract-frame", assetHandler.ExtractFrame)
 		}
 
 		storyboards := api.Group("/storyboards")