Add nix-gaming, Home Manager, and system improvements

- Add nix-gaming flake for gaming optimizations
- Add Home Manager for better user package management
- Enable zramSwap for memory compression
- Enable fwupd for firmware updates
- Enable power-profiles-daemon for power management
- Add PipeWire low-latency configuration
- Add platform optimizations from nix-gaming
- Add gaming tools: LACT, vkbasalt, discord
- Add dev tools: meld, dbeaver-bin, insomnia

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

flake.nix

@@ -22,9 +22,19 @@
       inputs.nixpkgs.follows = "nixpkgs";
       inputs.quickshell.follows = "quickshell";
     };
+
+    nix-gaming = {
+      url = "github:fufexan/nix-gaming";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    home-manager = {
+      url = "github:nix-community/home-manager";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
-  outputs = { self, nixpkgs, mango, quickshell, noctalia, ... }@inputs:
+  outputs = { self, nixpkgs, mango, quickshell, noctalia, nix-gaming, home-manager, ... }@inputs:
   let
     system = "x86_64-linux";
     lib = nixpkgs.lib;
@@ -38,6 +48,11 @@
       ./hosts/atlas/hardware-configuration.nix
       ./modules/common.nix
       mangoModule
+      home-manager.nixosModules.home-manager
+      {
+        home-manager.useGlobalPkgs = true;
+        home-manager.useUserPackages = true;
+      }
     ];
   in {
     nixosConfigurations = {