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/system/network.nix

@@ -0,0 +1,26 @@
+{ config, pkgs, ... }: {
+  # Network configuration
+  networking = {
+    hostName = "congenital-optimist";
+    hostId = "8425e349";
+    networkmanager.enable = true;
+    nftables.enable = true;
+    
+    # Firewall configuration
+    firewall = {
+      enable = true;
+      allowedTCPPorts = [ 22 ];
+      allowedUDPPorts = [ 22 ];
+    };
+  };
+
+  # VPN and remote access
+  services.tailscale.enable = true;
+  services.openssh.enable = true;
+
+  # ZFS services
+  services.zfs = {
+    autoScrub.enable = true;
+    trim.enable = true;
+  };
+}