refactor(nixpkgs): drop the repo-wide pkgs-x64 package set

Every remaining pkgs-x64 consumer runs only on x86_64-linux hosts, where the
native pkgs already carries the same allowUnfree config
(modules/nixos/base/nix.nix) and overlays (modules/base/overlays.nix), so
replace the references with pkgs and drop the extra nixpkgs instantiation
(which also removes an eval on aarch64-darwin).

media.nix keeps the native Zoom app on x86_64 hosts only, since zoom-us has
no aarch64 Linux build.

home/linux/gui/base/gaming.nix

@@ -1,6 +1,5 @@
 {
   pkgs,
-  pkgs-x64,
   osConfig,
   config,
   lib,
@@ -44,12 +43,12 @@ in
         # required by some games to fix problems
         bbe
       ])
-      ++ (with pkgs-x64; [
+      ++ (with pkgs; [
         # Heroic Games Launcher - primarily for Epic Games & GOG
         # https://heroicgameslauncher.com/
         (heroic.override {
           extraPkgs = _pkgs: [
-            pkgs.gamescope # aarch64
+            pkgs.gamescope
           ];
         })
       ]);
@@ -60,13 +59,13 @@ in
     # https://lutris.net/games?ordering=-popularity
     programs.lutris = {
       enable = true;
-      defaultWinePackage = pkgs-x64.proton-ge-bin;
+      defaultWinePackage = pkgs.proton-ge-bin;
       steamPackage = osConfig.programs.steam.package;
-      protonPackages = [ pkgs-x64.proton-ge-bin ];
-      winePackages = with pkgs-x64; [
+      protonPackages = [ pkgs.proton-ge-bin ];
+      winePackages = with pkgs; [
         wineWow64Packages.full
       ];
-      extraPackages = with pkgs-x64; [
+      extraPackages = with pkgs; [
         winetricks
         gamescope
         gamemode

home/linux/gui/base/media.nix

@@ -1,29 +1,32 @@
 {
   pkgs,
-  pkgs-x64,
+  lib,
   ...
 }:
 # media - control and enjoy audio/video
 {
-  home.packages = with pkgs; [
-    # audio control
-    pavucontrol
-    playerctl
-    pulsemixer
-    imv # simple image viewer
+  home.packages =
+    with pkgs;
+    [
+      # audio control
+      pavucontrol
+      playerctl
+      pulsemixer
+      imv # simple image viewer
 
-    # music
-    go-musicfox # TUI NetEase Cloud Music client; plays through mpv (configured below)
+      # music
+      go-musicfox # TUI NetEase Cloud Music client; plays through mpv (configured below)
 
-    # video/audio tools
-    libva-utils
-    vdpauinfo
-    vulkan-tools
-    mesa-demos
-    nvitop
+      # video/audio tools
+      libva-utils
+      vdpauinfo
+      vulkan-tools
+      mesa-demos
+      nvitop
+    ]
     # Zoom: Settings > Share Screen > Advanced > Screen Capture Mode on Wayland > PipeWire Mode.
-    (pkgs-x64.zoom-us)
-  ];
+    # zoom-us ships only an x86_64 Linux client, so the aarch64 host skips it.
+    ++ lib.optionals pkgs.stdenv.hostPlatform.isx86_64 [ pkgs.zoom-us ];
 
   programs.mpv = {
     enable = true;

home/linux/gui/i3/default.nix

@@ -1,6 +1,5 @@
 {
   pkgs,
-  pkgs-x64,
   config,
   lib,
   ...
@@ -58,7 +57,7 @@ let
 
     ${lib.optionalString cfg.cuaDriver ''
       # cua-driver sends content-free telemetry by default; turn it off.
-      ${pkgs-x64.cua-driver}/bin/cua-driver telemetry disable >/dev/null 2>&1 || true
+      ${pkgs.cua-driver}/bin/cua-driver telemetry disable >/dev/null 2>&1 || true
     ''}
   '';
 in
@@ -84,10 +83,10 @@ in
       ]
       ++ [
         # MCP server / CLI that drives the desktop (see overlays/computer-use-linux.nix).
-        pkgs-x64.computer-use-linux
+        pkgs.computer-use-linux
       ]
       ++ lib.optional cfg.vnc pkgs.x11vnc
-      ++ lib.optional cfg.cuaDriver pkgs-x64.cua-driver;
+      ++ lib.optional cfg.cuaDriver pkgs.cua-driver;
 
     # Headless X server.
     systemd.user.services.xvfb = {
@@ -202,7 +201,7 @@ in
           "DISPLAY=${display}"
           "XDG_SESSION_TYPE=x11"
         ];
-        ExecStart = "${pkgs-x64.cua-driver}/bin/cua-driver serve";
+        ExecStart = "${pkgs.cua-driver}/bin/cua-driver serve";
         Restart = "always";
         RestartSec = 2;
       };

modules/nixos/desktop/gaming.nix

@@ -1,6 +1,5 @@
 {
   pkgs,
-  pkgs-x64,
   nix-gaming,
   config,
   lib,
@@ -39,7 +38,7 @@ in
       #   ~/.steam/root        - A symlink to ~/.local/share/Steam
       #   ~/.steam             - Some Symlinks & user info
       enable = true;
-      package = pkgs-x64.steam;
+      package = pkgs.steam;
       # https://github.com/Winetricks/winetricks
       # Whether to enable protontricks, a simple wrapper for running Winetricks commands for Proton-enabled games.
       protontricks.enable = true;
@@ -55,8 +54,8 @@ in
       # each game's Properties -> Compatibility.
       # https://dawn.wine/dawn-winery/dwproton
       extraCompatPackages = [
-        pkgs-x64.dwproton-bin
-        pkgs-x64.proton-ge-bin
+        pkgs.dwproton-bin
+        pkgs.proton-ge-bin
       ];
     };
 

outputs/default.nix

@@ -56,15 +56,6 @@ let
           cudaCapabilities = [ "8.9" ];
         };
       };
-
-      pkgs-x64 = import nixpkgs {
-        system = "x86_64-linux";
-
-        # To use chrome, we need to allow the installation of non-free software
-        config.allowUnfree = true;
-
-        overlays = import ../overlays args;
-      };
     };
 
   # This is the args for all the haumea modules in this folder.