overlays/nix-monitored: don't override globally

Overriding globally would break nix-shell shebangs

nix/configurations/hetzner_benchmark.nix

@@ -44,8 +44,6 @@ in
         ];
       };
 
-      nix.package = pkgs.nix-monitored;
-
       system.nixos =
         let
           rev = lib.substring 0 8 sources.nixpkgs.revision;

nix/configurations/hydrogen.nix

@@ -49,8 +49,6 @@ in
         ];
       };
 
-      nix.package = pkgs.nix-monitored;
-
       system.nixos =
         let
           rev = lib.substring 0 8 sources.nixpkgs.revision;

nix/configurations/vanadium.nix

@@ -74,8 +74,6 @@ in
         ];
       };
 
-      nix.package = pkgs.nix-monitored;
-
       system.nixos =
         let
           rev = lib.substring 0 8 sources.nixpkgs.revision;

nix/overlays/nix-monitored.nix

@@ -1,10 +1,26 @@
 let
   sources = import ../../npins;
 in
-# The final nix is lix in this case
-final: prev: {
-  nix-monitored = sources.nix-monitored.asFlake.packages.${final.stdenv.hostPlatform.system}.default.override {
-    inherit (final) nix;
-    withNotify = false; # noisy, spams "command completed" even for nix shells
+final: prev:
+let
+  nix-monitored-noisy =
+    sources.nix-monitored.asFlake.packages.${final.stdenv.hostPlatform.system}.default.override
+      {
+        inherit (final)
+          nix # Use the nix the user wants, whether it's lix or nix
+          nix-output-monitor # don't use the nom pinned by nix-monitored
+          ;
+      };
+
+  nix-monitored = nix-monitored-noisy.override {
+    withNotify = false;
+  };
+in
+{
+  nixos-rebuild = prev.nixos-rebuild.override {
+    nix = nix-monitored-noisy;
+  };
+  nix-direnv = prev.nix-direnv.override {
+    nix = nix-monitored;
   };
 }