feat(nix): add HALO system configuration and user setup

- Added system configuration for the HALO machine, including hardware, sound, and remapping settings.
- Configured user-specific settings like session paths, favorite apps, and terminal customization.
- Introduced zram swap, SSD TRIM, and PipeWire priority tuning for performance optimization.

systems/x86_64-linux/halo/default.nix

@@ -0,0 +1,123 @@
+{
+  pkgs,
+  lib,
+  ...
+}:
+with lib;
+with lib.metacfg;
+{
+  imports = [
+    ./hardware-configuration.nix
+    ./xremap.nix
+  ];
+
+  powerManagement.cpuFreqGovernor = "performance";
+
+  services.openssh = {
+    enable = true;
+  };
+
+  services.tailscale.enable = true;
+  services.resolved.enable = true;
+
+  metacfg = {
+    hardware.wooting.enable = true;
+    base.enable = true;
+    gui.enable = true;
+    nix-ld.enable = true;
+    nix.enable = true;
+    podman.enable = true;
+    secureboot.enable = true;
+    homeprinter.enable = true;
+    build.enable = true;
+
+    system = {
+      limits = {
+        enable = true;
+        nofileLimit = 32768;
+        memlockLimit = 32768;
+      };
+    };
+
+    # User configuration
+    tools = {
+      direnv.enable = true;
+    };
+    user.extraGroups = [
+      "docker"
+      "dialout"
+      "tss"
+    ];
+    system.kernelTweaks.enable = true;
+  };
+
+  system.autoUpgrade = {
+    enable = true;
+    operation = "boot";
+    allowReboot = false;
+  };
+
+  nixpkgs.config.permittedInsecurePackages = [
+    "electron-27.3.11"
+  ];
+
+  # Additional kernel tuning beyond the module defaults
+  boot.kernel.sysctl = {
+    # Reduce swap usage (you have zram)
+    "vm.swappiness" = 10;
+    # Prefer keeping directory/inode caches
+    "vm.vfs_cache_pressure" = 50;
+    # Faster dirty page writeback
+    "vm.dirty_ratio" = 10;
+    "vm.dirty_background_ratio" = 5;
+  };
+
+  # SSD TRIM support
+  services.fstrim = {
+    enable = true;
+    interval = "weekly";
+  };
+
+  programs.steam = {
+    enable = true;
+  };
+
+  environment.systemPackages = with pkgs; [
+    attic-client
+    azure-cli
+    claude-code
+    claude-desktop-with-fhs
+    desktop-file-utils
+    gnome-terminal
+    gnome-remote-desktop
+    gtypist
+    k9s
+    klavaro
+    kubectl
+    kubectx
+    logseq
+    nvtopPackages.amd
+    obsidian
+    piper-tts
+    tipp10
+    uv
+    vscode
+    cider-2
+  ];
+
+  # zram swap with zstd compression for better performance
+  zramSwap = {
+    algorithm = "zstd";
+    memoryPercent = 50;
+  };
+
+  services.ratbagd.enable = true;
+
+  virtualisation = {
+    libvirtd.enable = true;
+    docker.enable = true;
+    podman.dockerCompat = false;
+  };
+
+  system.stateVersion = "25.11";
+}

systems/x86_64-linux/halo/hardware-configuration.nix

@@ -0,0 +1,54 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{
+  config,
+  lib,
+  modulesPath,
+  ...
+}:
+
+{
+  imports = [
+    (modulesPath + "/installer/scan/not-detected.nix")
+  ];
+
+  boot.initrd.availableKernelModules = [
+    "nvme"
+    "xhci_pci"
+    "thunderbolt"
+    "usbhid"
+    "uas"
+    "sd_mod"
+    "sdhci_pci"
+  ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-amd" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" = {
+    device = "/dev/disk/by-uuid/d22a1052-f142-44c0-993c-76b15c27b2b3";
+    fsType = "ext4";
+    options = [ "noatime" ];
+
+  };
+
+  fileSystems."/boot" = {
+    device = "/dev/disk/by-uuid/EDA8-FB8B";
+    fsType = "vfat";
+    options = [
+      "fmask=0077"
+      "dmask=0077"
+    ];
+  };
+
+  /*
+    swapDevices = [
+      { device = "/dev/disk/by-uuid/708a53d6-4e68-4587-96e4-aa5e2c1df51a"; }
+    ];
+  */
+  swapDevices = [ ];
+
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+  hardware.cpu.amd.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
+}

systems/x86_64-linux/halo/sound.nix

@@ -0,0 +1,40 @@
+{ ... }:
+{
+  services.pipewire.wireplumber.extraConfig."51-audio-priorities" = {
+    "monitor.alsa.rules" = [
+      {
+        matches = [
+          { "node.name" = "alsa_output.pci-0000_73_00.1.hdmi-stereo"; }
+        ];
+        actions = {
+          update-props = {
+            "priority.session" = 2000;
+            "priority.driver" = 2000;
+          };
+        };
+      }
+      {
+        matches = [
+          { "node.name" = "alsa_output.usb-R__DE_Microphones_R__DE_NT-USB_Mini_6893EA23-00.analog-stereo"; }
+        ];
+        actions = {
+          update-props = {
+            "priority.session" = 1500;
+            "priority.driver" = 1500;
+          };
+        };
+      }
+      {
+        matches = [
+          { "node.name" = "alsa_output.usb-Generic_USB_Audio-00.HiFi__SPDIF__sink"; }
+        ];
+        actions = {
+          update-props = {
+            "priority.session" = 1000;
+            "priority.driver" = 1000;
+          };
+        };
+      }
+    ];
+  };
+}

systems/x86_64-linux/halo/xremap.nix

@@ -0,0 +1,21 @@
+{ ... }:
+{
+  metacfg.services.xremap = {
+    enable = true;
+    deviceNames = [
+      "Hangsheng MonsGeek Keyboard"
+      "HS Galaxy100 Keyboard"
+    ];
+    config = {
+      keymap = [
+        {
+          remap = {
+            LeftAlt-C = "COPY";
+            LeftAlt-V = "PASTE";
+            LeftAlt-X = "CUT";
+          };
+        }
+      ];
+    };
+  };
+}