Use albumen.png as OG image for root URL

Root album leaves @og_image_rel nil so layout.erb falls back to
/img/albumen.png; photo-based OG image only applies to sub-albums.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/app.rb b/app.rb
index cf371c8..5aba1b4 100644
--- a/app.rb
+++ b/app.rb
@@ -250,13 +250,13 @@ def browse_album(rel)
     photo_name    = File.basename(params[:photo])
     @og_image_rel = rel.empty? ? photo_name : "#{rel}/#{photo_name}"
     @og_use_media = true
-  else
+  elsif !rel.empty?
     first_img = @entries.find { |e| %i[image video].include?(e[:type]) }
     @og_image_rel = if first_img
-      rel.empty? ? first_img[:name] : "#{rel}/#{first_img[:name]}"
+      "#{rel}/#{first_img[:name]}"
     else
       cover = cover_candidates(dir).first
-      cover ? (rel.empty? ? cover : "#{rel}/#{cover}") : nil
+      cover ? "#{rel}/#{cover}" : nil
     end
   end