fix(P1): 修复渲染进度条0% + unified引擎缩略图不显示 (#548)

Co-authored-by: xiaoxia <dev@xiaoxiajianji.com>
Co-committed-by: xiaoxia <dev@xiaoxiajianji.com>

apps/worker/video_processing/render_adapter.py

@@ -63,6 +63,7 @@ class RenderAdapterResult:
     success: bool
     output_url: str = ""
     output_path: Path | None = None
+    thumbnail_url: str = ""
     duration: float = 0.0
     file_size: int = 0
     width: int = 0
@@ -224,6 +225,22 @@ class RenderAdapter:
             storage_key = f"rendered/{plan_id}/{job_id or plan_id}.mp4"
             output_url = upload_to_oss(result.output_path, storage_key)
 
+            self._report_progress(progress_cb, 90.0, "生成封面缩略图")
+
+            # 5. 生成缩略图（在清理临时目录前）
+            thumbnail_url = ""
+            try:
+                from video_processing.thumbnail_generator import generate_and_upload_thumbnail
+
+                thumb_storage_key = f"rendered/{plan_id}/thumbnail.jpg"
+                thumbnail_url = generate_and_upload_thumbnail(str(result.output_path), thumb_storage_key)
+            except Exception as thumb_err:
+                logger.warning(
+                    "[render-adapter] 缩略图生成失败（不影响主流程）: plan_id=%s error=%s",
+                    plan_id,
+                    thumb_err,
+                )
+
             self._report_progress(progress_cb, 100.0, "渲染完成")
 
             logger.info(
@@ -242,6 +259,7 @@ class RenderAdapter:
                 success=True,
                 output_url=output_url or "",
                 output_path=result.output_path,
+                thumbnail_url=thumbnail_url,
                 duration=result.duration,
                 file_size=result.file_size,
                 width=result.width,