Persist the .ssh known_hosts.

nix/configuration/configuration.nix

@@ -37,6 +37,7 @@
     ./roles/qemu
     ./roles/wireguard
     ./roles/bsnes
+    ./roles/ssh
   ];
 
   nix.settings.experimental-features = [

nix/configuration/roles/ssh/default.nix

@@ -0,0 +1,19 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  environment.persistence."/persist" = lib.mkIf (!config.me.buildingIso) {
+    hideMounts = true;
+    users.talexander = {
+      files = [
+        ".ssh/known_hosts"
+      ];
+    };
+  };
+}