Fix FastAPI doc pages.

We can't directly use frozen dataclasses from pydcs in our interface
because pydantic can't process them. Pydantic is able to automatically
convert to our modelview type from the pydcs type though.

game/server/flights/models.py

@@ -2,17 +2,17 @@ from __future__ import annotations
 
 from uuid import UUID
 
-from dcs.mapping import LatLng
 from pydantic import BaseModel
 
 from game.ato import Flight
 from game.ato.flightstate import InFlight
+from game.server.leaflet import LeafletPoint
 
 
 class FlightJs(BaseModel):
     id: UUID
     blue: bool
-    position: LatLng | None
+    position: LeafletPoint | None
 
     @staticmethod
     def for_flight(flight: Flight) -> FlightJs: