chore(nix): refactor SGX configuration for nixtee1

- Removed SGX-specific settings including `aesmd_dcap`, `sgx_default_qcnl.conf`, and `security.tpm2` configurations.
- Updated `system.stateVersion` and switched kernel modules to `kvm-amd`.
- Adjusted disk UUIDs and removed unused `/boot` filesystem definition.

systems/x86_64-linux/nixtee1/default.nix

@@ -0,0 +1,63 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+with lib;
+with lib.metacfg;
+{
+  imports = [ ./hardware-configuration.nix ];
+
+  boot.kernelPackages = lib.mkOverride 0 pkgs.linuxPackages_latest;
+
+  metacfg = {
+    base.enable = true;
+    nix-ld.enable = true;
+    nix.enable = true;
+    podman.enable = true;
+    user.extraGroups = [
+      "docker"
+      "sgx"
+    ];
+    tools = {
+      direnv.enable = true;
+    };
+  };
+
+  virtualisation = {
+    docker.enable = true;
+    podman.dockerCompat = false;
+  };
+
+  system.autoUpgrade = {
+    enable = true;
+    operation = "switch";
+    allowReboot = true;
+  };
+
+  networking.wireless.enable = false; # Enables wireless support via wpa_supplicant.
+
+  networking.firewall.allowPing = true;
+
+  powerManagement.cpuFreqGovernor = "ondemand";
+
+  systemd.user.extraConfig = "DefaultLimitNOFILE=32768";
+
+  security.pam.loginLimits = [
+    {
+      domain = "*";
+      item = "nofile";
+      type = "-";
+      value = "32768";
+    }
+    {
+      domain = "*";
+      item = "memlock";
+      type = "-";
+      value = "32768";
+    }
+  ];
+
+  system.stateVersion = "25.05";
+}