Ensure a unique ID for supply routes.

List indexes are not a reliable list key unless the list is static.
Indexes will be reused when games are loaded, which prevents the state
from updating reliably.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2167

client/src/api/_liberationApi.ts

@@ -428,6 +428,7 @@ export type Tgo = {
   sidc: string;
 };
 export type SupplyRoute = {
+  id: string;
   points: LatLng[];
   front_active: boolean;
   is_sea: boolean;

client/src/components/supplyrouteslayer/SupplyRoutesLayer.tsx

@@ -7,8 +7,8 @@ export default function SupplyRoutesLayer() {
   const routes = useAppSelector(selectSupplyRoutes).routes;
   return (
     <LayerGroup>
-      {routes.map((route, idx) => {
-        return <SupplyRoute key={idx} route={route} />;
+      {routes.map((route) => {
+        return <SupplyRoute key={route.id} route={route} />;
       })}
     </LayerGroup>
   );