Refactor and improve external URL checks

- Move external URL checks to its own module under `tests/`. This
  separates them from integration test, addressing long runs and
  frequent failures that led to ignoring test results.
- Move `check-desktop-runtime-errors` to `tests/checks` to keep all
  test-related checks into one directory.
- Replace `ts-node` with `vite` for running
  `check-desktop-runtime-errors` to maintain a consistent execution
  environment across checks.
- Implement a timeout for each fetch call.
- Be nice to external sources, wait 5 seconds before sending another
  request to an URL under same domain. This solves rate-limiting issues.
- Instead of running test on every push/pull request, run them only
  weekly.
- Do not run tests on each commit/PR but only scheduled (weekly) to
  minimize noise.
- Fix URLs are not captured correctly inside backticks or parenthesis.

tests/checks/external-urls/StatusChecker/UrlPerDomainGrouper.ts

@@ -0,0 +1,19 @@
+export function groupUrlsByDomain(urls: string[]): string[][] {
+  const domains = new Set<string>();
+  const urlsWithDomain = urls.map((url) => ({
+    url,
+    domain: extractDomain(url),
+  }));
+  for (const url of urlsWithDomain) {
+    domains.add(url.domain);
+  }
+  return Array.from(domains).map((domain) => {
+    return urlsWithDomain
+      .filter((url) => url.domain === domain)
+      .map((url) => url.url);
+  });
+}
+
+function extractDomain(url: string): string {
+  return url.split('://')[1].split('/')[0].toLowerCase();
+}