Reddit: Use session cookies.

app/logical/source/extractor/reddit.rb

@@ -59,6 +59,10 @@ def share_url
         parsed_urls.find(&:share_id)
       end
 
+      def http
+        super.cookies(reddit_session: Danbooru.config.reddit_session_cookie)
+      end
+
       def api_url
         "https://reddit.com/gallery/#{work_id}" if work_id.present?
       end

config/danbooru_default_config.rb

@@ -591,6 +591,10 @@ def bluesky_identifier
     def bluesky_password
     end
 
+    # Your Reddit "reddit_session" cookie.
+    def reddit_session_cookie
+    end
+
     # A list of tags that should be removed when a post is replaced. Regexes allowed.
     def post_replacement_tag_removals
       %w[replaceme .*_sample resized upscaled downscaled md5_mismatch