feat: demucs status查询端点（读Redis）+ worker usage说明

scripts/demucs-status.dspy

@@ -0,0 +1,54 @@
+# Demucs 任务状态查询
+# 部署到: /data/ymq/demucs-service/app/api/demucs-status.dspy
+# GET /demucs/api/demucs-status?task_id=xxx
+import json
+
+task_id = params_kw.task_id
+if not task_id:
+    return {"error": "task_id is required"}
+
+env = request._run_ns
+longtasks = env.longtasks
+
+# longtasks 内部通过 Redis 存储结果，key 格式: {queue_name}:result:{task_id}
+import redis.asyncio as redis
+r = redis.Redis(host='127.0.0.1', port=6379, db=0, decode_responses=True)
+
+# 尝试获取结果
+result_key = f"demucs:result:{task_id}"
+raw = await r.get(result_key)
+
+if raw:
+    data = json.loads(raw)
+    return {
+        "task_id": task_id,
+        "status": "SUCCEEDED",
+        "vocals_url": data.get("vocals_path", ""),
+        "accompaniment_url": data.get("accompaniment_path", ""),
+        "duration": data.get("duration", 0),
+        "usage": data.get("usage", {"次": 1}),
+    }
+
+# 检查是否在队列中
+queue_key = f"demucs:queue"
+in_queue = await r.lrange(queue_key, 0, -1)
+for item in in_queue:
+    try:
+        item_data = json.loads(item)
+        if item_data.get("task_id") == task_id:
+            return {"task_id": task_id, "status": "queued"}
+    except:
+        pass
+
+# 检查是否在处理中
+processing_key = f"demucs:processing"
+processing = await r.get(processing_key)
+if processing:
+    try:
+        proc_data = json.loads(processing)
+        if proc_data.get("task_id") == task_id:
+            return {"task_id": task_id, "status": "processing"}
+    except:
+        pass
+
+return {"task_id": task_id, "status": "not_found"}