chore(nix): add Tailscale to default packages

- Included `tailscale` in the default package set for Darwin services.
- Ensures availability of Tailscale for secure connectivity and VPN management.

modules/darwin/services/base/default.nix

@@ -1,7 +1,8 @@
-{ config
-, lib
-, pkgs
-, ...
+{
+  config,
+  lib,
+  pkgs,
+  ...
 }:
 with lib;
 with lib.metacfg;
@@ -32,6 +33,7 @@ in
         ripgrep
         rrsync
         sops
+        tailscale
         tmux
         vim
         wget