feat: 添加 _buf_payload 缓冲区以增强 DB.py 的数据处理能力

main.py

@@ -658,7 +658,8 @@ def search_worker(payload, kitem, flag):
                 if v_list:
                     break
                 time.sleep(2)
-
+        if not v_list:
+            v_list = []
         return True, flag, payload, kitem, v_list  # 成功
     except Exception as e:
         print(f"[线程异常] {kitem['keyword']} → {e}")
@@ -691,8 +692,9 @@ def integrate_data_parallel():
                 rollback[f_flag].append(payload)
                 continue
 
-            # —— 写库：可按你原来的 upsert / flush 逻辑 ——
             for item in v_list:
+                if not v_list:
+                    continue
                 DBSA.upsert_video({
                     "keyword": kitem["keyword"],
                     "v_name": kitem["v_name"],