Update flake to flake-parts

flake.nix

@@ -2,18 +2,16 @@
   description = "Tasksquire";
 
   inputs = {
-    nixpkgs.url = "nixpkgs/nixos-unstable";
-    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs {
-          inherit system;
-        };
+  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
 
-        tasksquire = pkgs.buildGoModule {
+      perSystem = { config, self', inputs', pkgs, system, ... }: {
+        packages.tasksquire = pkgs.buildGoModule {
           pname = "tasksquire";
           version = "0.1.0";
           src = ./.;
@@ -32,13 +30,13 @@
             mainProgram = "tasksquire";
           };
         };
-      in
-      {
-        packages.default = tasksquire;
-        packages.tasksquire = tasksquire;
-        apps.default = flake-utils.lib.mkApp { drv = tasksquire; };
 
+        # Set the default package
+        packages.default = self'.packages.tasksquire;
+
+        # Development shell
         devShells.default = pkgs.mkShell {
+          inputsFrom = [ self'.packages.tasksquire ];
           buildInputs = with pkgs; [
             go_1_24
             gcc
@@ -50,14 +48,9 @@
             go-tools
             gotests
             delve
-            taskwarrior3
-            timewarrior
           ];
           CGO_CFLAGS = "-O";
         };
-
-        # Backward compatibility
-        devShell = self.devShells.${system}.default;
-      });
+      };
+    };
 }
-