feat: implement backend API clients for multi-marketplace integration and frontend service layer

backend/ym_api/services/orders.py

@@ -0,0 +1,45 @@
+from typing import Dict, Any, Optional
+from ..client import YMClient
+
+class OrdersService:
+    """Service to handle Yandex Market Orders."""
+    
+    def __init__(self, client: YMClient):
+        self.client = client
+
+    def get_list(self, campaign_id: Optional[str] = None, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        """
+        Get list of orders for a specific campaign.
+        Endpoint: /campaigns/{campaignId}/orders.json
+        """
+        cid = campaign_id or self.client.campaign_id
+        if not cid:
+            raise ValueError("campaign_id must be provided either in the method call or client initialization.")
+            
+        return self.client.get(f"/campaigns/{cid}/orders.json", params=params)
+
+    def get_order(self, order_id: str, campaign_id: Optional[str] = None) -> Dict[str, Any]:
+        """
+        Get info about a specific order.
+        Endpoint: /campaigns/{campaignId}/orders/{orderId}.json
+        """
+        cid = campaign_id or self.client.campaign_id
+        if not cid:
+            raise ValueError("campaign_id must be provided either in the method call or client initialization.")
+            
+        return self.client.get(f"/campaigns/{cid}/orders/{order_id}.json")
+
+    def update_status(self, order_id: str, status: str, substatus: Optional[str] = None, campaign_id: Optional[str] = None) -> Dict[str, Any]:
+        """
+        Update the status of an order.
+        Endpoint: /campaigns/{campaignId}/orders/{orderId}/status.json
+        """
+        cid = campaign_id or self.client.campaign_id
+        if not cid:
+            raise ValueError("campaign_id must be provided either in the method call or client initialization.")
+            
+        payload = {"order": {"status": status}}
+        if substatus:
+            payload["order"]["substatus"] = substatus
+            
+        return self.client.put(f"/campaigns/{cid}/orders/{order_id}/status.json", data=payload)