Move common host features to features-nixos folder

features-nixos/global/nix.nix

@@ -0,0 +1,46 @@
+{outputs, ...}: {
+  # Apply overlays
+  nixpkgs = {
+    # TODO: apply this to hm and nixos without duplicate code
+    overlays = builtins.attrValues outputs.overlays;
+    config = {
+      nvidia.acceptLicense = true;
+      allowUnfree = true;
+      allowUnfreePredicate = _: true; # TODO: what is this
+      warn-dirty = false;
+      permittedInsecurePackages = [
+        "olm-3.2.16"
+      ];
+    };
+  };
+
+  # optimize at every build, slows down builds
+  # better to do optimise.automatic for regular optimising
+  # nix.settings.auto-optimise-store = lib.mkDefault true;
+  nix.settings.experimental-features = [
+    "nix-command"
+    "flakes"
+    "ca-derivations"
+  ];
+  # warn-dirty = false;
+
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 30d";
+    persistent = true;
+  };
+  nix.optimise = {
+    automatic = true;
+    dates = ["weekly"]; # Optional; allows customizing optimisation schedule
+    persistent = true;
+  };
+
+  programs.nix-ld.enable = true;
+
+  # TODO: is this useful?, what does it do?
+  # nix.settings.flake-registry = ""; # Disable global flake registry
+  # Add each flake input as a registry and nix_path
+  # registry = lib.mapAttrs (_: flake: { inherit flake; }) flakeInputs;
+  # nixPath = lib.mapAttrsToList (n: _: "${n}=flake:${n}") flakeInputs;
+}