Orchestrate script-to-final-video production with a strict stage-gated workflow (outline → episode_plan → storyboard → storyboard_images → render), using Seedream image generation, Seedance multi-shot rendering, checkpoint-based confirmation/resume, and optional FFmpeg concatenation. Use when converting txt/json/staged artifacts into storyboard videos and a final merged mp4.

通过严格的阶段门控工作流（大纲 → 集计划 → 分镜脚本 → 分镜图 → 渲染）协调脚本到最终视频的生成过程，使用Seedream生成图像、Seedance多镜头渲染、基于检查点的确认与恢复功能，以及可选的FFmpeg合并。适用于将txt/json/分阶段生成的文件转换为分镜视频和最终合并的mp4文件。