[add] Add the completion status of knowledge extraction to the stream output.

api/app/core/memory/storage_services/extraction_engine/extraction_orchestrator.py

@@ -384,6 +384,14 @@ class ExtractionOrchestrator:
         
         logger.info(f"陈述句提取完成，共提取 {len(all_statements)} 条陈述句")
 
+        # 试运行模式下，所有分块提取完成后发送完成事件
+        if self.progress_callback and self.is_pilot_run:
+            await self.progress_callback(
+                "knowledge_extraction_complete",
+                f"陈述句提取完成，共提取 {len(all_statements)} 条",
+                {"total_statements": len(all_statements), "total_chunks": total_chunks}
+            )
+
         return dialog_data_list
 
     async def _extract_triplets(