feat: 任务详情 LLM 请求数（cost_records 存 completions）

cloud/worker.py

@@ -5332,7 +5332,8 @@ class Worker:
                 cached_input_tokens=usage_total.get(
                     "cached_input_tokens", 0),
                 usd_micros=micros,
-                source="actual", fallback_count=fallback_count)
+                source="actual", fallback_count=fallback_count,
+                completions=usage_total.get("completions", 0))
         else:
             micros = None
             total = estimate_tokens(task.get("prompt") or "", stdout)