feat: initial NixOS home lab infrastructure setup

- Add modular flake-based NixOS configuration
- Implement GitOps foundation with CI/CD pipeline
- Create comprehensive documentation and branching strategy
- Add modular desktop environments (GNOME, Cosmic, Sway)
- Configure virtualization stack (Incus, Libvirt, Podman)
- Set up development tools and hardware-specific modules
- Establish user configuration with literate programming support

This commit represents the completion of Phase 1: Flakes Migration
with modular configuration, virtualization, and GitOps foundation.

modules/virtualization/incus.nix

@@ -0,0 +1,19 @@
+{ config, pkgs, ... }:
+{
+  virtualisation.incus = {
+    enable = true;
+    ui.enable = true;
+    package = pkgs.incus;
+  };
+
+  environment.systemPackages = with pkgs; [
+    incus
+    lxc
+  ];
+  users.users.geir = {
+    extraGroups = [ 
+      "incus-admin"
+    ];
+  };
+  networking.firewall.allowedTCPPorts = [ 8443 ];
+}

modules/virtualization/libvirt.nix

@@ -0,0 +1,21 @@
+{ config, pkgs, ... }: {
+  virtualisation.libvirtd = {
+    enable = true;
+    qemu = {
+      package = pkgs.qemu_kvm;
+      runAsRoot = true;
+      swtpm.enable = true;
+      ovmf = {
+        enable = true;
+        packages = [ pkgs.OVMFFull.fd ];
+      };
+    };
+  };
+  
+  environment.systemPackages = with pkgs; [
+    qemu_kvm
+    libvirt
+    virt-manager
+    virt-viewer
+  ];
+}

modules/virtualization/podman.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }: {
+  virtualisation.podman = {
+    enable = true;
+    dockerCompat = true;
+    dockerSocket.enable = true;
+    defaultNetwork.settings.dns_enabled = true;
+  };
+
+  environment.systemPackages = with pkgs; [
+    podman-tui
+    podman-compose
+    buildah
+    skopeo
+  ];
+  
+  # Enable container runtime for desktop integration
+  virtualisation.containers.enable = true;
+}