"Show Full Post" button doesn't work in subfolder installations

That is easy to test, try

url = "https://tecnoblog.net/noticias/governo-renova-app-da-cnh-para-baratear-obtencao-do-documento/"
response = TopicEmbed.find_remote(url)
puts "Remote fetch success: #{response.present?}"
puts "Remote body present: #{response&.body.present?}"
puts "Remote body length: #{response&.body&.length || 0}"
puts "Remote title: #{response&.title}"
puts "Remote body: #{response&.body&.truncate(500)}"