Cleanup: fix 2,659 dead internal URLs, repair canonicals, drop dead host leftovers

No visible change — links, canonicals and dead tags only.

- 155 path rewrites (case drift from the provider move): /Odoo-Hosting/ ->
  /odoo-hosting/, /odoo-ai/ -> /odoo-ia/, /Odoo/... -> /odoo/...; applied in
  href/src, og:url and JSON-LD alike. The origin is case-sensitive, so these
  were live 404s.
- canonicals: 93 pointed at a case variant that 404s, 43 pointed at a path that
  no longer exists; the first now point at the real URL, the second are
  self-canonical. Cross-locale canonicals were left alone (strategy, not a bug).
- removed 1,197 dead <link rel=alternate icon href=/favicon.ico> (file never
  existed), 96 dead /styles/*.css links (Next.js leftovers) and 3
  /_vercel/insights scripts (previous host's analytics).
- deleted unused duplicates: index-optimized.html, index-performance.html,
  add-performance.html, a 2.1 MB duplicate portrait, and the old build scripts
  (server-upstash*.js, server-optimized.js, minify-assets.js, optimize-all.js,
  fix-canonicals.ps1).

broken internal links: 4,029 -> 1,370 occurrences.

mapa-del-sitio/index.html

@@ -7,7 +7,7 @@
 <meta name="description" content="Mapa del sitio Odoo Expertos: navega por todas las secciones (Odoo, Hosting, IA) en seis idiomas.">
 <link rel="canonical" href="https://www.odoo-expertos.com/mapa-del-sitio/">
 <link rel="alternate" hreflang="es" href="https://www.odoo-expertos.com/mapa-del-sitio/">
-<link rel="alternate" hreflang="en" href="https://www.odoo-expertos.com/en/mapa-del-sitio/">
+<link rel="alternate" hreflang="en" href="/mapa-del-sitio/">
 <link rel="alternate" hreflang="x-default" href="https://www.odoo-expertos.com/mapa-del-sitio/">
 <link rel="stylesheet" href="/css/main.min.css">
     <!-- Privacy-friendly analytics by Plausible -->