Adds flake registry aliases.

modules/nixos/core/default.nix

@@ -2,6 +2,7 @@
   config,
   pkgs,
   lib,
+  inputs,
   ...
 }:
 let
@@ -73,6 +74,21 @@ in
           trusted-users = users;
           warn-dirty = false;
         };
+
+        registry = {
+          nixpkgs.flake = inputs.nixpkgs;
+          nixconf.flake = inputs.self;
+        };
+        nixPath = [
+          "nixpkgs=flake:nixpkgs"
+          "nixos-config=flake:nixconf"
+        ];
+      };
+
+      home-manager = {
+        useGlobalPkgs = true;
+        useUserPackages = true;
+        backupFileExtension = "hm-bak";
       };
 
       programs.neovim = {