LocalSend: use module to open 53317

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

common.nix

@@ -188,6 +188,9 @@ in
   # Enable network-manager
   networking.networkmanager.enable = true;
 
+  # LocalSend — the module also opens 53317 tcp/udp (discovery + transfer)
+  programs.localsend.enable = true;
+
   # Fish shell
   programs.fish.enable = true;
   users.defaultUserShell = pkgs.fish;
@@ -210,7 +213,6 @@ in
   # Add packages
   environment.systemPackages = with pkgs; [
       git
-      localsend
       nvd
       nix-output-monitor
       jq