[ci] verify deployed index artifact and enforce release checks

scripts/verify-deployed-index-html.mjs

@@ -0,0 +1,59 @@
+#!/usr/bin/env node
+
+const VERSION_MARKUP_PATTERN = /seed\.\s*zap\.\s*subscribe\.\s*<\/h2>\s*<div[^>]*>\s*v:\s*[a-f0-9]{8}\s*•\s*\d{4}-\d{2}-\d{2}\s*<\/div>/i;
+
+function parseArgs(argv) {
+  const args = {
+    url: process.env.DEPLOY_INDEX_URL ?? ''
+  };
+
+  for (let i = 0; i < argv.length; i += 1) {
+    const arg = argv[i];
+
+    if (arg === '--url') {
+      args.url = argv[i + 1] ?? args.url;
+      i += 1;
+      continue;
+    }
+
+    if (arg === '--help' || arg === '-h') {
+      console.log('Usage: node scripts/verify-deployed-index-html.mjs --url <https://example.com/index.html>');
+      process.exit(0);
+    }
+
+    throw new Error(`Unknown argument: ${arg}`);
+  }
+
+  if (!args.url) {
+    throw new Error('Missing deployed index URL. Pass --url or set DEPLOY_INDEX_URL.');
+  }
+
+  return args;
+}
+
+async function main() {
+  const args = parseArgs(process.argv.slice(2));
+  const response = await fetch(args.url, {
+    headers: {
+      Accept: 'text/html'
+    }
+  });
+
+  if (!response.ok) {
+    throw new Error(`Unable to fetch deployed index.html (${args.url}): HTTP ${response.status}`);
+  }
+
+  const html = await response.text();
+  if (!VERSION_MARKUP_PATTERN.test(html)) {
+    throw new Error(
+      `Deployed index.html is missing version markup under the slogan at ${args.url} (expected: v: <8-char-hash> • <date>).`
+    );
+  }
+
+  console.log(`Deployed index verification passed: ${args.url} includes slogan version markup.`);
+}
+
+main().catch((error) => {
+  console.error(error.message);
+  process.exit(1);
+});