refactor(merchant): move address formatting logic to pipeline stage

The address formatting fallback logic was moved from the projection definition to the pipeline stage in merchant service for better maintainability and consistency with other pipeline operations.

app/models/optimized_projections.py

@@ -28,27 +28,8 @@ CARD_FIELDS = {
     "city": 1,
     "merchant_category": 1,
     "merchant_subcategory": 1,
-    # Include entire address object
+    # Include entire address object (formatted_address fallback handled in pipeline)
     "address": 1,
-    # Ensure address.formatted_address is populated with a sensible fallback
-    "address.formatted_address": {
-        "$ifNull": [
-            "$address.formatted_address",
-            {
-                "$trim": {
-                    "input": {
-                        "$concat": [
-                            {"$ifNull": ["$address.street", ""]},
-                            {"$literal": " "},
-                            {"$ifNull": ["$address.area", ""]},
-                            {"$literal": " "},
-                            {"$ifNull": ["$city", ""]}
-                        ]
-                    }
-                }
-            }
-        ]
-    },
     "promotions": 1,
 }
 

app/services/merchant.py

@@ -119,6 +119,30 @@ def build_optimized_merchant_pipeline(
     
     # Add go_live_from normalization
     pipeline.append(get_go_live_from_normalized_stage())
+
+    # Ensure formatted address is present by adding a fallback
+    pipeline.append({
+        "$addFields": {
+            "address.formatted_address": {
+                "$ifNull": [
+                    "$address.formatted_address",
+                    {
+                        "$trim": {
+                            "input": {
+                                "$concat": [
+                                    {"$ifNull": ["$address.street", ""]},
+                                    {"$literal": " "},
+                                    {"$ifNull": ["$address.area", ""]},
+                                    {"$literal": " "},
+                                    {"$ifNull": ["$city", ""]}
+                                ]
+                            }
+                        }
+                    }
+                ]
+            }
+        }
+    })
     
     # Add distance calculation if needed
     if include_distance and user_lat and user_lng: