feat: migrate from modules to features

features/openssh.nix

@@ -0,0 +1,25 @@
+{
+  nixos =
+    { lib, config, ... }:
+    {
+      options = {
+        openssh.port = lib.mkOption {
+          type = lib.types.port;
+          default = 22;
+        };
+      };
+
+      config = {
+        services.openssh = {
+          enable = true;
+          ports = [ config.openssh.port ];
+          settings = {
+            PasswordAuthentication = false;
+            AllowUsers = null;
+            PermitRootLogin = "no";
+            StreamLocalBindUnlink = "yes";
+          };
+        };
+      };
+    };
+}