add custom huggingface_hub packages (learning from hf-cli's authentication workflow)

hosts/packages/huggingface_hub/flake.nix

@@ -0,0 +1,35 @@
+# Template: https://nixos-and-flakes.thiscute.world/development/intro
+{
+  description = "Humanity's Last Exam - Devshell";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+  };
+
+  outputs = {nixpkgs, ...}: let
+    system = "x86_64-linux";
+    pkgs = import nixpkgs {
+      inherit system;
+    };
+    python = pkgs.python312.override {
+      self = python;
+      packageOverrides = pyfinal: pyprev: {
+        huggingface-hub = pyfinal.callPackage ./huggingface_hub.nix {};
+        hf-xet = pyfinal.callPackage ./hf-xet.nix {};
+      };
+    };
+  in {
+    devShells."${system}".default = pkgs.mkShell {
+      packages = [
+        (python.withPackages (pypkgs: [
+          pypkgs.huggingface-hub
+        ]))
+      ];
+
+      shell = "${pkgs.bash}/bin/bash";
+      shellHook = ''
+        alias hf=huggingface-cli
+      '';
+    };
+  };
+}