nix: add vps setup

nix/hosts/thought/configuration.nix

@@ -0,0 +1,69 @@
+{ config, pkgs, ... }:
+{
+  imports = [
+    ./disko-config.nix
+    ./hardware-configuration.nix
+  ];
+
+  system.stateVersion = "24.05";
+
+  swapDevices = [
+    {
+      device = "/swapfile";
+      size = 2048; # MB
+    }
+  ];
+
+  boot.loader.grub = {
+    efiSupport = true;
+    efiInstallAsRemovable = true;
+  };
+
+  time.timeZone = "Europe/Kyiv";
+  i18n.defaultLocale = "en_US.UTF-8";
+
+  networking = {
+    hostName = "vps";
+    useDHCP = true;
+    # Interface names will be auto-detected in hardware-configuration.nix
+    # Using generic DHCP setting
+    interfaces = {};
+    firewall = {
+      enable = true;
+      allowedTCPPorts = [80 443];
+    };
+  };
+
+  environment.systemPackages = with pkgs; [
+    neovim
+    git
+    htop
+    tmux
+  ];
+
+  services = {
+    caddy.enable = true;
+    openssh = {
+      enable = true;
+      settings = {
+        PasswordAuthentication = false;
+        PermitRootLogin = "no";
+      };
+    };
+  };
+
+  nix = {
+    gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 30d";
+    };
+    settings = {
+      auto-optimise-store = true;
+      experimental-features = [
+        "nix-command"
+        "flakes"
+      ];
+    };
+  };
+}