refactor!: restructure and document configuration

shared/nixos/system.nix

@@ -0,0 +1,84 @@
+{ pkgs, config, ... }:
+
+{
+  # Kernel
+  boot.kernelPackages = pkgs.linuxPackages_zen;
+
+  boot.initrd.kernelModules = [
+    "v4l2loopback"
+    "zenergy"
+  ];
+
+  boot.extraModulePackages = [
+    config.boot.kernelPackages.v4l2loopback
+    config.boot.kernelPackages.zenergy # Allows fetching power draw information on AMD CPUs
+  ];
+
+  # Configure v4l2loopback
+  boot.extraModprobeConfig = ''
+    options v4l2loopback devices=1 video_nr=1 card_label="Virtual camera" exclusive_caps=1
+  '';
+
+  # Bootloader.
+  boot.loader = {
+    systemd-boot = {
+      enable = true;
+      configurationLimit = 10;
+    };
+
+    efi.canTouchEfiVariables = true;
+  };
+
+  # Enables zram.
+  zramSwap.enable = true;
+
+  # Enable networking
+  networking.networkmanager.enable = true;
+
+  # Enable sound with pipewire.
+  services.pulseaudio.enable = false;
+  services.pipewire = {
+    enable = true;
+    audio.enable = true;
+
+    alsa.enable = true;
+    alsa.support32Bit = true;
+
+    pulse.enable = true;
+  };
+
+  # Enable fish system-wide to integrate with nixpkgs.
+  programs.fish.enable = true;
+
+  # Set fish as the default shell for all users.
+  users.defaultUserShell = pkgs.fish;
+
+  # Enable CUPS to print documents.
+  services.printing.enable = true;
+
+  # Enable the OpenSSH daemon.
+  services.openssh = {
+    enable = true;
+
+    settings = {
+      PasswordAuthentication = false;
+      PermitRootLogin = "no";
+      StreamLocalBindUnlink = "yes";
+    };
+  };
+
+  # Enable GPG.
+  programs.gnupg.agent = {
+    enable = true;
+    enableSSHSupport = true;
+  };
+
+  # Enable polkit,
+  security.polkit.enable = true;
+
+  # install an agent to interface with it,
+  environment.systemPackages = with pkgs; [ polkit_gnome ];
+
+  # And enable GNOME keyring for registering keys.
+  services.gnome.gnome-keyring.enable = true;
+}