treewide: separate ssh keys

nixos/openssh.nix

@@ -0,0 +1,17 @@
+{ self, ... }:
+{
+  services.openssh = {
+    enable = true;
+
+    settings = {
+      ClientAliveInterval = 300;
+      KbdInteractiveAuthentication = false;
+      PasswordAuthentication = false;
+      PermitRootLogin = "no";
+    };
+  };
+
+  users.users.root.openssh.authorizedKeys.keys = builtins.attrValues {
+    inherit (import "${self}/lib/ssh/keys.nix") error javalsai;
+  };
+}