feat(seo): sitemap, OG/canonical/hreflang, JSON-LD i18n

Add sitemap.xml route enumerating recipes, apologetik args, prayers, and
faith hubs. Drop /static/ from robots.txt — was blocking JSON-LD recipe
images from Google. Add reusable Seo component (OG/Twitter/canonical) and
wire into homepage, faith hub, recipes hub, and apologetik index.

Faith and recipe layouts now emit canonical + hreflang automatically by
swapping known lang slugs; deeper paths whose inner segments aren't safely
translatable (recipe [name], prayer [prayer], apologetik [argId]) are
skipped at the layout and may opt-in per page.

Recipe JSON-LD HowToStep names and baking instructions now resolve via
the recipes i18n table (jsonld_step / jsonld_bake / jsonld_for_duration +
existing at_temp) instead of being hardcoded German — English /recipes/
pages were emitting "Schritt N" in their schema.

static/robots.txt

@@ -2,4 +2,11 @@ User-agent: GPTBot
 Disallow: /
 
 User-agent: *
-Disallow: /static/
+Disallow: /api/
+Disallow: /login
+Disallow: /logout
+Disallow: /tasks
+Disallow: /settings
+Disallow: /register
+
+Sitemap: https://bocken.org/sitemap.xml