Filter offer edges from route stages

Offer edges connect offer nodes to locations and are not
transport stages. Filter them out in _build_route_from_edges()
to avoid showing 0km "offer" steps in the route stepper.

geo_app/schema.py

@@ -795,6 +795,11 @@ def _build_route_from_edges(path_edges, node_docs):
     if not path_edges:
         return None
 
+    # Фильтруем offer edges - это не транспортные этапы, а связь оффера с локацией
+    path_edges = [(f, t, e) for f, t, e in path_edges if e.get('transport_type') != 'offer']
+    if not path_edges:
+        return None
+
     stages = []
     current_edges = []
     current_type = None