chrome.runtime.onInstalled.addListener(async () => {
  await chrome.scripting.unregisterContentScripts({ ids: ["suppress-alert"] }).catch(() => {});
  await chrome.scripting.registerContentScripts([{
    id: "suppress-alert",
    matches: ["https://calendar.google.com/*"],
    js: ["suppress.js"],
    runAt: "document_start",
    world: "MAIN"
  }]);
});