fix(landing): remove Twilio claims, add BRL pricing, add SEO tags

- Replace "via Twilio" with "coming soon" in both EN and PT-BR
- Add R$59/seat reference to EN pricing card
- Add OG tags, Twitter Card, canonical URL to both versions
- Add robots.txt and sitemap.xml

sitemap.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+  <url>
+    <loc>https://batida.io/</loc>
+    <changefreq>weekly</changefreq>
+    <priority>1.0</priority>
+  </url>
+  <url>
+    <loc>https://batida.io/pt-br</loc>
+    <changefreq>weekly</changefreq>
+    <priority>0.9</priority>
+  </url>
+</urlset>