feat: 添加视频生成功能增强和多维度计费系统适配

- 视频生成: 增强 video_handler，重构 task_poller，新增 telemetry
- 计费系统: 适配新的 signature 格式，支持 video 任务类型回退
- 数据库迁移: 添加 api_family/endpoint_kind 字段和 video_formats

src/api/public/videos.py

@@ -90,6 +90,21 @@ async def download_video_content_sora(
     )
 
 
+@router.post("/v1/videos/{task_id}/remix")
+async def remix_video_sora(
+    task_id: str, http_request: Request, db: Session = Depends(get_db)
+) -> Any:
+    adapter = OpenAIVideoAdapter()
+    return await pipeline.run(
+        adapter=adapter,
+        http_request=http_request,
+        db=db,
+        mode=adapter.mode,
+        api_format_hint=adapter.allowed_api_formats[0],
+        path_params={"task_id": task_id},
+    )
+
+
 # -------------------- Gemini Veo compatible --------------------