fix(guest_model): sanitize guest data before MongoDB writes

Add data sanitization step using prepare_for_db() function before all MongoDB update operations to ensure proper data format and prevent potential issues with date/time fields

app/models/guest_model.py

@@ -52,9 +52,11 @@ class GuestModel:
                     guest_doc["is_default"] = True
             guests.append(guest_doc)
 
+            # Sanitize for MongoDB (convert date to datetime, strip tzinfo, etc.)
+            sanitized_guests = prepare_for_db(guests)
             update_res = await BookMyServiceUserModel.collection.update_one(
                 {"customer_id": customer_id},
-                {"$set": {"guests": guests}}
+                {"$set": {"guests": sanitized_guests}}
             )
 
             if update_res.modified_count > 0:
@@ -148,9 +150,11 @@ class GuestModel:
                 logger.warning(f"Embedded guest not found for update: {guest_id} (user {customer_id})")
                 return False
 
+            # Sanitize for MongoDB before write
+            sanitized_guests = prepare_for_db(guests)
             result = await BookMyServiceUserModel.collection.update_one(
                 {"customer_id": customer_id},
-                {"$set": {"guests": guests}}
+                {"$set": {"guests": sanitized_guests}}
             )
 
             if result.modified_count > 0:
@@ -179,9 +183,11 @@ class GuestModel:
                 logger.warning(f"Embedded guest not found for deletion: {guest_id} (user {customer_id})")
                 return False
 
+            # Sanitize for MongoDB before write
+            sanitized_new_guests = prepare_for_db(new_guests)
             result = await BookMyServiceUserModel.collection.update_one(
                 {"customer_id": customer_id},
-                {"$set": {"guests": new_guests}}
+                {"$set": {"guests": sanitized_new_guests}}
             )
 
             if result.modified_count > 0:
@@ -272,9 +278,11 @@ class GuestModel:
                         g["updated_at"] = now
             if not found:
                 return False
+            # Sanitize for MongoDB before write
+            sanitized_guests = prepare_for_db(guests)
             res = await BookMyServiceUserModel.collection.update_one(
                 {"customer_id": customer_id},
-                {"$set": {"guests": guests}}
+                {"$set": {"guests": sanitized_guests}}
             )
             return True
         except Exception as e: