feat: Add canonical URL and enforce non-www domain

- Configure Nginx to redirect www.rectorspace.com → rectorspace.com (301)
- Add canonical link tag in layout for SEO clarity
- All variants (http/https, www/non-www) now redirect to https://rectorspace.com
- Prevents duplicate content penalty from search engines
- Consolidates SEO authority to single domain

Author: rz1989s

app/views/layouts/application.html.erb

@@ -9,6 +9,9 @@
     <%= csrf_meta_tags %>
     <%= csp_meta_tag %>
 
+    <%# Canonical URL for SEO - always use non-www %>
+    <link rel="canonical" href="https://rectorspace.com<%= request.path %>">
+
     <%= yield :head %>
 
     <%# Enable PWA manifest for installable apps (make sure to enable in config/routes.rb too!) %>