const config = {
  version: 1,
  settings: { theme: "dark", fontSize: 14 },
  tags: ["beta", "v1"],
};

Object.seal(config);
Object.freeze(config.settings);

config.version = 99;
config.newProp = "ignored";
delete config.tags;

config.settings.theme = "light";
config.settings.newKey = "ignored";

config.tags.push("v2");
config.tags[0] = "stable";

console.log(
  config.version,
  config.newProp,
  config.settings.theme,
  config.tags
);