chore: separate frontend from backend

flake.nix

@@ -1,7 +1,7 @@
 {
   inputs = {
     nixpkgs.url = "github:cachix/devenv-nixpkgs/rolling";
-    systems.url = "github:nix-systems/default";
+    flake-utils.url = "github:numtide/flake-utils";
     alejandra = {
       url = "github:kamadorueda/alejandra/4.0.0";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -10,10 +10,6 @@
       url = "github:cachix/devenv";
       inputs.nixpkgs.follows = "nixpkgs";
     };
-    rust-overlay = {
-      url = "github:oxalica/rust-overlay";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
   };
 
   nixConfig = {
@@ -30,27 +26,18 @@
   outputs = {
     self,
     nixpkgs,
-    devenv,
-    systems,
-    rust-overlay,
     alejandra,
+    flake-utils,
     ...
-  } @ inputs: let
-    forEachSystem = nixpkgs.lib.genAttrs (import systems);
-  in {
-    formatter = forEachSystem (system: alejandra.defaultPackage.${system});
-    packages = forEachSystem (system: import ./backend/nix/package.nix { inherit rust-overlay inputs system; });
-    devShells = forEachSystem (
-      system: let
-        pkgs = nixpkgs.legacyPackages.${system};
-      in {
-        backend = import ./backend/nix/shell.nix {
-          inherit inputs pkgs system self rust-overlay;
-        };
-        frontend = import ./frontend/shell.nix {
-          inherit inputs pkgs self;
-        };
-      }
-    );
-  };
+  } @ inputs:
+  flake-utils.lib.eachDefaultSystem (
+    system: let
+      pkgs = nixpkgs.legacyPackages.${system};
+    in {
+      formatter = alejandra.defaultPackage.${system};
+      devShell = import ./nix/shell.nix {
+        inherit inputs pkgs self;
+      };
+    }
+  );
 }