fix(seo): legal.html canonical, host-case normalisation, BlogPosting x15, blog body domain typo

Four follow-up defects found beyond the 2026-10-27 SEO audit (no copy changes):

1. legal.html canonical was https://ODOO4projects.com/legal — uppercase host AND a
   path that 404s. Now https://odoo4projects.com/legal.html. The file's og:url keeps
   its path /legal but its host is lowercased (path fix awaiting a decision).
2. The no-"4" domain typo in reader-visible <pre><code> body text of
   blog/posts/{guide-migrate-enterprise,speed-run-deploy,my-first-post}.html:
   odooprojects.com -> odoo4projects.com. Domain string only, no other wording.
3. Lowercase host in every machine-read value: the robots.txt Sitemap line, the
   homepage + de/ + es/ Organization JSON-LD url / contactPoint.url / offers[].url,
   legal.html og:url, and the four absolute self-URL hrefs in blog posts,
   odoo/support.html and email/trial-confirmation.html. Display text untouched
   (support@ODOO4projects.com stays as written).
4. One BlogPosting per blog post (15), every value taken from the page itself:
   headline = its <h1>, datePublished = its visible post-meta date, url = its own
   canonical, author/publisher = the Organization the site already publishes,
   image = its og:image where one exists (omitted on the 10 posts that have none).

Empire ">950.00", FAQPage on support.html, the blog-chrome change and the bootcamp
date conflict are untouched — decisions pending with the user.

robots.txt

@@ -1,3 +1,3 @@
 User-agent: *
 Allow: /
-Sitemap: https://ODOO4projects.com/sitemap.xml
+Sitemap: https://odoo4projects.com/sitemap.xml