增加视频生成过程详细信息的持久化l; 优化session管理逻辑;

pixelle_video/services/__init__.py

@@ -21,6 +21,7 @@ Services:
 - MediaService: Media generation (image & video)
 - VideoService: Video processing
 - FrameProcessor: Frame processing orchestrator
+- PersistenceService: Task metadata and storyboard persistence
 - ComfyBaseService: Base class for ComfyUI-based services
 """
 
@@ -30,6 +31,7 @@ from pixelle_video.services.tts_service import TTSService
 from pixelle_video.services.media import MediaService
 from pixelle_video.services.video import VideoService
 from pixelle_video.services.frame_processor import FrameProcessor
+from pixelle_video.services.persistence import PersistenceService
 
 # Backward compatibility alias
 ImageService = MediaService
@@ -42,5 +44,6 @@ __all__ = [
     "ImageService",  # Backward compatibility
     "VideoService",
     "FrameProcessor",
+    "PersistenceService",
 ]