feat(nftables): Add NFTables integration for kernel-level forwarding and update documentation, tests, and helper functions

test/test.nftables-integration.simple.ts

@@ -56,7 +56,7 @@ tap.test('NFTables integration tests', async () => {
       host: 'localhost',
       port: 8080
     }, {
-      ports: { from: 9000, to: 9100 },
+      ports: [{ from: 9000, to: 9100 }],
       protocol: 'tcp'
     })
   ];