flake: add custom cache

host/modules/common.nix

@@ -11,10 +11,15 @@
   };
 
   config = {
+    nix.settings = {
+      keep-going = true;
+      extra-substituters = [ "https://nix.codrs.ru/main" ];
+      extra-trusted-public-keys = [ "main:kpwMe+9BsGJ/IUb7i3iadaV38y5/Yuqoct0mf7wI9ds=" ];
+      experimental-features = [ "nix-command" "flakes" ];
+    };
     networking.hostName = hostname;
     time.timeZone = lib.mkDefault "Europe/Moscow";
     i18n.defaultLocale = lib.mkDefault "ru_RU.UTF-8";
-    nix.settings.experimental-features = [ "nix-command" "flakes" ];
     system.stateVersion = "23.05";
   };
 }