refactor(flake): wrap xonsh as a package

flake.nix

@@ -55,13 +55,22 @@
       ref = "master";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    hetch = {
+      type = "git";
+      url = "https://codeberg.org/amadaluzia/hetch.git";
+      ref = "master";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
   };
   outputs = inputs @ {
+    self,
     nixpkgs,
     flake-parts,
     ...
   }: let
-    lib = nixpkgs.lib.extend (import ./lib {inherit inputs;});
+    lib = nixpkgs.lib.extend (import ./lib {inherit inputs self;});
   in
     flake-parts.lib.mkFlake {
       inherit inputs;
@@ -71,48 +80,8 @@
       imports = [
         ./hosts
         ./overlays
-        inputs.git-hooks-nix.flakeModule
+        ./shells
       ];
       flake = {inherit lib;};
-      perSystem = {
-        config,
-        pkgs,
-        ...
-      }: {
-        pre-commit = {
-          check.enable = true;
-          settings.hooks = {
-            alejandra.enable = true;
-            nil.enable = true;
-            shellcheck.enable = true;
-            prettier.enable = true;
-            ruff.enable = true;
-            ruff-format.enable = true;
-            shfmt.enable = true;
-            deadnix = {
-              enable = true;
-              args = ["-e"];
-            };
-            statix = {
-              enable = true;
-              args = ["fix"];
-            };
-          };
-        };
-        devShells.default = config.pre-commit.devShell;
-        devShells.haskell = pkgs.mkShell {
-          name = "haskell";
-          packages = builtins.attrValues {
-            inherit (pkgs) ghc;
-            inherit
-              (pkgs.haskellPackages)
-              cabal-install
-              haskell-language-server
-              ormolu
-              ;
-          };
-        };
-        formatter = pkgs.alejandra;
-      };
     };
 }