Add NixOS dual-configuration setup (dev and gaming profiles)

Co-authored-by: ragusa-it <196988693+ragusa-it@users.noreply.github.com>

flake.nix

@@ -0,0 +1,50 @@
+{
+  description = "NixOS - Isolated Gaming & Dev configurations";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    mango = {
+      url = "github:DreamMaoMao/mango";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    quickshell = {
+      url = "github:outfoxxed/quickshell";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    noctalia = {
+      url = "github:noctalia-dev/noctalia-shell";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.quickshell.follows = "quickshell";
+    };
+  };
+
+  outputs = { self, nixpkgs, mango, quickshell, noctalia, ... }@inputs:
+  let
+    system = "x86_64-linux";
+    specialArgs = { inherit inputs system; };
+
+    # IMPORTANT: Replace <hostname> with actual hostname
+    commonModules = [
+      ./hosts/<hostname>/hardware-configuration.nix
+      ./modules/common.nix
+      mango.nixosModules.mango
+    ];
+  in {
+    nixosConfigurations = {
+      # Development configuration
+      dev = nixpkgs.lib.nixosSystem {
+        inherit system specialArgs;
+        modules = commonModules ++ [ ./modules/dev.nix ];
+      };
+
+      # Gaming configuration
+      gaming = nixpkgs.lib.nixosSystem {
+        inherit system specialArgs;
+        modules = commonModules ++ [ ./modules/gaming.nix ];
+      };
+    };
+  };
+}