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

test/test.route-utils.ts

@@ -189,7 +189,7 @@ tap.test('Route Validation - validateRouteAction', async () => {
   // Invalid action (missing static root)
   const invalidStaticAction: IRouteAction = {
     type: 'static',
-    static: {}
+    static: {} as any // Testing invalid static config without required 'root' property
   };
   const invalidStaticResult = validateRouteAction(invalidStaticAction);
   expect(invalidStaticResult.valid).toBeFalse();