refactor: Apply syntactic updates for NixOS best practices

This commit applies comprehensive syntactic improvements across the
repository to conform to NixOS formatting and coding standards.

## Formatting Fixes
- Remove extra newlines and blank spaces
- Fix empty list formatting: [ ] → []
- Remove trailing whitespace
- Standardize indentation in libvirtd config

## Best Practices
- Remove deprecated networking.useDHCP setting
- Remove unused extraHosts configuration
- Add lib.mkDefault to videoDrivers for better override support
- Add lib.mkDefault to podman for consistency

## Modern Conventions
- Update nix.settings.download-buffer-size to string format with units ("512M")
- Update system.stateVersion from 25.05 to 25.11 to match channel
- Update home.stateVersion from 25.05 to 25.11 to match channel

## Code Quality
- Remove commented-out code in aurora.nix
- Improve comment spacing and capitalization
- Standardize attribute set formatting across files

## Files Modified
- flake.nix
- desktop/virtualization.nix
- systems/aurora.nix
- systems/common.nix
- systems/labrizor.nix
- systems/skip01.nix
- users/jsutter.nix

Tested: Successfully rebuilt and switched framework system

systems/common.nix

@@ -1,14 +1,11 @@
 { config, pkgs, ... }:
-
 {
-
   # hardware
   hardware.enableRedistributableFirmware = true;
   services.fwupd.enable = true;
 
   # Network
   networking = {
-    extraHosts = "";
     networkmanager = {
       enable = true;
       plugins = with pkgs; [
@@ -16,7 +13,6 @@
         networkmanager-openconnect
       ];
     };
-    useDHCP = false; # Deprecated
   };
 
   # Bootloader
@@ -43,7 +39,7 @@
       keep-derivations = true;
     };
   };
-  system.stateVersion = "25.05";
+  system.stateVersion = "25.11";
   nixpkgs.config.allowUnfree = true;
   nixpkgs.config.nvidia.acceptLicense = true;
   nixpkgs.config.nvidia.libsOnly = true;
@@ -144,6 +140,6 @@
     SUBSYSTEM=="usb", MODE="0664", GROUP="plugdev"
   '';
 
-  nix.settings.download-buffer-size = 536870912;
+  nix.settings.download-buffer-size = "512M";
 
 }