Import locomotive availability descriptors with overlay context

crates/rrt-runtime/src/step.rs

@@ -1157,6 +1157,7 @@ mod tests {
             players: Vec::new(),
             selected_player_id: None,
             trains: Vec::new(),
+            locomotive_catalog: Vec::new(),
             territories: Vec::new(),
             company_territory_track_piece_counts: Vec::new(),
             company_territory_access: Vec::new(),