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

backend/flowwow_api/services/orders.py

@@ -0,0 +1,29 @@
+from typing import Dict, Any
+from ..client import FlowwowClient
+
+class OrdersService:
+    """Service to handle Flowwow Orders."""
+    
+    def __init__(self, client: FlowwowClient):
+        self.client = client
+
+    def get_new_orders(self, limit: int = 50) -> Dict[str, Any]:
+        """
+        Get list of new, unprocessed orders.
+        Endpoint: /orders/new
+        """
+        return self.client.get("/orders/new", params={"limit": limit})
+
+    def accept_order(self, order_id: str) -> Dict[str, Any]:
+        """
+        Accept an order for processing.
+        Endpoint: /orders/{order_id}/accept
+        """
+        return self.client.post(f"/orders/{order_id}/accept")
+
+    def upload_photo(self, order_id: str, image_url: str) -> Dict[str, Any]:
+        """
+        Upload a photo of the completed order before shipping.
+        Endpoint: /orders/{order_id}/photo
+        """
+        return self.client.post(f"/orders/{order_id}/photo", data={"image_url": image_url})