Only show the booking calendars after the lead form is sent

/contact/book/ now needs ?submitted=1 (set in the GHL form redirect) to load the
calendars; other visitors get a prompt that links to the form. The page is noindex
and out of the sitemap, the contact page card points to the form, and visitors are
sent back to the language they filled the form in.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build.mjs

@@ -37,7 +37,7 @@ for (const name of pages) {
     await mkdir(dirname(file), { recursive: true });
     await writeFile(file, fingerprint(html));
   }
-  urls.push(def.path);
+  if (!def.noindex) urls.push(def.path);
   console.log('built', def.path);
 }
 for (const [l, set] of Object.entries(missing)) {