Move NavMesh out of MapModel.

game/server/navmesh/routes.py

@@ -0,0 +1,20 @@
+from fastapi import APIRouter, Depends
+
+from game import Game
+from game.server import GameContext
+from .models import NavMeshPolyJs
+from ..leaflet import ShapelyUtil
+
+router: APIRouter = APIRouter(prefix="/navmesh")
+
+
+@router.get("/", response_model=list[NavMeshPolyJs])
+def get(for_player: bool, game: Game = Depends(GameContext.get)) -> list[NavMeshPolyJs]:
+    mesh = game.coalition_for(for_player).nav_mesh
+    return [
+        NavMeshPolyJs(
+            poly=ShapelyUtil.poly_to_leaflet(p.poly, game.theater),
+            threatened=p.threatened,
+        )
+        for p in mesh.polys
+    ]