feat(seo): add /what-can-i-use-odoo-for/ guide page, linked from the homepage and support FAQ

Modelled on odoo-community-upgrade.html (top bar, band rhythm, FAQ details).
Copy published verbatim from the copywriter's 2026-10-28 file: 58-char title,
157-char meta, the six outbound internal links and the WebPage+Article+FAQPage+
BreadcrumbList @graph. Nine FAQ questions marked plausible-event-name=FAQ (no
event fires on page load). Sitemap + llms.txt list the new URL. Inbound links:
one from the homepage FAQ card, one from the support FAQ answer. Nothing else
moves; no footer change.

sitemap.xml

@@ -42,6 +42,12 @@
     <changefreq>monthly</changefreq>
     <priority>0.9</priority>
   </url>
+  <url>
+    <loc>https://odoo4projects.com/what-can-i-use-odoo-for/</loc>
+    <lastmod>2026-10-28</lastmod>
+    <changefreq>monthly</changefreq>
+    <priority>0.6</priority>
+  </url>
   <url>
     <loc>https://odoo4projects.com/odooityourself.html</loc>
     <lastmod>2026-10-26</lastmod>