Fix POI distance calculation for buy listings

The distance calculator always queried the rentlisting table regardless of
listing type because get_listings() defaulted to RentListing when called
without query_parameters. Added a listing_type parameter to get_listings()
and _get_model_for_query() so callers can select the correct table directly.

services/poi_distance_calculator.py

@@ -7,7 +7,7 @@ from typing import Callable
 import aiohttp
 
 from config.routing_config import RoutingConfig
-from models.listing import BuyListing, ListingType, RentListing
+from models.listing import ListingType
 from models.poi import PointOfInterest
 from models.poi_distance import POIDistance
 from rec.osrm_client import osrm_table
@@ -53,10 +53,9 @@ async def calculate_poi_distances(
         config = RoutingConfig.from_env()
 
     # Load listings with coordinates
-    model = RentListing if listing_type == ListingType.RENT else BuyListing
     listings = await listing_repo.get_listings(
         only_ids=listing_ids,
-        query_parameters=None,
+        listing_type=listing_type,
     )
     if not listings:
         logger.info("No listings found for distance calculation")