fix: SEO — prevent Google from indexing /text instead of main page

- Add X-Robots-Tag: noindex, nofollow header to /text endpoint
- Add Link: canonical header pointing to HTML version
- Add Disallow: /text to robots.txt
- Update sitemap.xml lastmod to 2026-04-09

static/robots.txt

@@ -13,6 +13,10 @@ Disallow: /api/internal/
 Disallow: /.git/
 Disallow: /.env
 
+# Plain text version — prevent duplicate content indexing
+# Canonical HTML version at / should be indexed instead
+Disallow: /text
+
 # =============================================================================
 # SITEMAPS & AI CONTENT
 # =============================================================================

static/sitemap.xml

@@ -5,7 +5,7 @@
   <!-- English Version -->
   <url>
     <loc>https://juan.andres.morenorub.io/?lang=en</loc>
-    <lastmod>2024-10-18</lastmod>
+    <lastmod>2026-04-09</lastmod>
     <changefreq>monthly</changefreq>
     <priority>1.0</priority>
     <xhtml:link rel="alternate" hreflang="es" href="https://juan.andres.morenorub.io/?lang=es"/>
@@ -15,7 +15,7 @@
   <!-- Spanish Version -->
   <url>
     <loc>https://juan.andres.morenorub.io/?lang=es</loc>
-    <lastmod>2024-10-18</lastmod>
+    <lastmod>2026-04-09</lastmod>
     <changefreq>monthly</changefreq>
     <priority>1.0</priority>
     <xhtml:link rel="alternate" hreflang="es" href="https://juan.andres.morenorub.io/?lang=es"/>
@@ -25,7 +25,7 @@
   <!-- Default (redirects to English) -->
   <url>
     <loc>https://juan.andres.morenorub.io/</loc>
-    <lastmod>2024-10-18</lastmod>
+    <lastmod>2026-04-09</lastmod>
     <changefreq>monthly</changefreq>
     <priority>0.9</priority>
   </url>
@@ -33,7 +33,7 @@
   <!-- Health Check Endpoint -->
   <url>
     <loc>https://juan.andres.morenorub.io/health</loc>
-    <lastmod>2024-10-18</lastmod>
+    <lastmod>2026-04-09</lastmod>
     <changefreq>daily</changefreq>
     <priority>0.3</priority>
   </url>