feat: remove contact form and switch canonical domain to mnqcatering.com

Drop the non-functional contact form (no backend wired up) and keep
the WhatsApp/phone contact path as the single call to action. Also
point site config, robots.txt, llms.txt, and every on-page domain
reference at www.mnqcatering.com ahead of the DNS cutover.

src/layouts/MainLayout.astro

@@ -30,7 +30,7 @@ const {
   structuredData,
 } = Astro.props;
 
-const site = Astro.site ?? new URL('https://mnq.elkazurrotaberna.es');
+const site = Astro.site ?? new URL('https://www.mnqcatering.com');
 const canonicalUrl = new URL(canonical ?? Astro.url.pathname, site).toString();
 const ogImageUrl = new URL(ogImage, site).toString();
 const baseStructuredData = {
@@ -57,7 +57,7 @@ const structuredDataScripts = [
       ? [structuredData]
       : []) as Array<Record<string, unknown>>),
 ];
-const umamiHost = Astro.site ? Astro.site.origin : 'https://mnq.elkazurrotaberna.es';
+const umamiHost = Astro.site ? Astro.site.origin : 'https://www.mnqcatering.com';
 const rawUmamiUrl = Astro.url ? import.meta.env.PUBLIC_UMAMI_URL : undefined;
 const umamiWebsiteId = import.meta.env.PUBLIC_UMAMI_WEBSITE_ID;
 const normalizedUmamiUrl = rawUmamiUrl