nixos: expose all args to nixosSystem via _banananetwork_systemArgs

nix/nixos/default.nix

@@ -13,15 +13,18 @@ let
         outputs.nixosModules.withDepends
         { home-manager.sharedModules = [ outputs.homeManagerModules.default ]; }
       ] ++ modules;
-    in
-    nixpkgs.lib.nixosSystem {
+      systemArgs = {
         modules = modsExtended;
-      specialArgs = {
-        flake = flakeArg;
-      };
+        # be aware: specialArgs will break in my nixos integration tests
         inherit system;
       };
     in
+    nixpkgs.lib.nixosSystem systemArgs
+    // {
+      # expose module cleanly
+      _banananetwork_systemArgs = systemArgs;
+    };
+in
 {
 
   "x13yz" = nixosSystem {