split home-manager into their own submodules

modules/dev/nix/common.nix

@@ -0,0 +1,45 @@
+{
+  pkgs,
+  hostName ? null,
+}:
+let
+  packages = builtins.attrValues {
+    inherit (pkgs)
+      nixfmt-rfc-style
+      cachix
+      nixd
+      deadnix
+      statix
+      mcp-nixos
+      ;
+  };
+in
+{
+  inherit packages;
+  devShell = pkgs.mkShell {
+    inherit packages;
+    name = "nix-dev-shell";
+    shellHook = ''
+      echo "❄️  Nix dev environment"
+    '';
+  };
+  shellAliases = {
+    nixformat = ''
+      deadnix -e && \
+      nix run nixpkgs#nixfmt-tree && \
+      statix fix
+    '';
+  }
+  // (
+    if hostName == null then
+      { }
+    else
+      {
+        nix-push-cache = ''
+          nix build $NH_FLAKE#nixosConfigurations.${hostName}.config.system.build.toplevel \
+          --print-out-paths --fallback --max-jobs 100 --cores 0 |
+          nix run nixpkgs#attic-client -- push lan:nixos --stdin
+        '';
+      }
+  );
+}