[nixbox] Use neovim, openssl, opencode, from pkgs-unstable.

hosts/nixbox/configuration.nix

@@ -254,6 +254,9 @@ in
     };
   };
 
+  # Enable firewall and only allw some ports.
+  networking.firewall.enable = false;
+
   system.stateVersion = "25.11"; # Did you read the comment?
 }
 

hosts/nixbox/home.nix

@@ -3,6 +3,7 @@
   inputs,
   config,
   pkgs,
+  pkgs-unstable,
   ssh-agent-switcher,
   user,
   ...
@@ -41,6 +42,7 @@ in {
 
   # Custom options for my packages.
   nvim = {
+    package = pkgs-unstable.neovim;
     enable = true;
   };
   ghostty = {
@@ -79,6 +81,9 @@ in {
       prismlauncher
 
       # Misc
+      pkgs-unstable.opencode
+      pkgs-unstable.claude-code
+      pkgs-unstable.openssl
       # zig
       fastfetch
       fzf