feat(vpnserver): add nftables-backed destination policy enforcement for TUN mode

ts/smartvpn.plugins.ts

@@ -8,7 +8,8 @@ import * as events from 'events';
 export { path, fs, os, url, events };
 
 // @push.rocks
+import * as smartnftables from '@push.rocks/smartnftables';
 import * as smartpath from '@push.rocks/smartpath';
 import * as smartrust from '@push.rocks/smartrust';
 
-export { smartpath, smartrust };
+export { smartnftables, smartpath, smartrust };