FEATURE: add bumped_before query param for topic list

app/assets/javascripts/discourse/controllers/discovery-sortable.js.es6

@@ -8,7 +8,8 @@ export const queryParams = {
   max_posts: { replace: true, refreshModel: true },
   q: { replace: true, refreshModel: true },
   tags: { replace: true },
-  before: { replace: true, refreshModel: true}
+  before: { replace: true, refreshModel: true},
+  bumped_before: { replace: true, refreshModel: true}
 };
 
 // Basic controller options

lib/topic_query.rb

@@ -14,6 +14,7 @@ class TopicQuery
     @public_valid_options ||=
       %i(page
          before
+         bumped_before
          topic_ids
          exclude_category_ids
          category
@@ -600,6 +601,12 @@ class TopicQuery
         end
       end
 
+      if bumped_before = options[:bumped_before]
+        if (bumped_before = bumped_before.to_i) > 0
+          result = result.where('topics.bumped_at < ?', bumped_before.to_i.days.ago)
+        end
+      end
+
       if status = options[:status]
         case status
         when 'open'