feat(landing): add Odoo Hosting 2027 comparison page

New page odoo-hosting-2027.html (feature + lifetime-cost comparison tables,
Odoo Online exclusion, Enterprise growth path, JSON-LD). Links it from the
homepage pricing CTA, adds it to sitemap.xml, adds llms.txt for AI-SEO.

index.html

@@ -469,6 +469,7 @@
           </div>
         </div>
         <p class="pricing-cta-note">Save money, less administration</p>
+        <p class="pricing-cta-note"><a href="odoo-hosting-2027.html"><strong>Compare every way to host Odoo in 2027 &rarr;</strong></a></p>
       </div>
     </section>