update flake.lock with new versions for Homebrew and other dependencies; modify manage.sh to use sudo for rebuild commands; add gnu-tar and freelens to homebrew apps; set primary user in system configuration

modules/darwin/system/system.nix

@@ -1,6 +1,8 @@
 { config, lib, ... }:
 
-{ 
+{
+  system.primaryUser = config._module.args.username;
+ 
   system.defaults.screencapture = {
     location = "~/Documents/Screenshots"; # Set default screenshot location
     # Add more screencapture settings here
@@ -22,8 +24,4 @@
   system.defaults.WindowManager.EnableStandardClickToShowDesktop = false; # Disable/Enable standard click to show desktop
   # You can add more Mac defaults here as well...
 
-  system.activationScripts.postUserActivation.text = ''
-    # Following line should allow us to avoid a logout/login cycle
-    /System/Library/PrivateFrameworks/SystemAdministration.framework/Resources/activateSettings -u
-  ''; # Activate settings after user activation
 }