Add limited-searchability activitypub support

app/lib/activitypub/activity/create.rb

@@ -480,6 +480,8 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
       nil
     elsif audience_searchable_by.any? { |uri| ActivityPub::TagManager.instance.public_collection?(uri) }
       :public
+    elsif audience_searchable_by.include?('as:Limited')
+      :limited
     elsif audience_searchable_by.include?(@account.followers_url)
       :private
     else
@@ -503,16 +505,16 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
       return nil if searchability.nil?
 
       searchability = :public  if searchability == 'public'
-      searchability = :unlisted if searchability == 'followers'
-      searchability = :direct   if searchability == 'private'
-      searchability = :private  if searchability == 'reactors'
+      searchability = :private if searchability == 'followers'
+      searchability = :limited if searchability == 'private'
+      searchability = :direct  if searchability == 'reactors'
     end
 
     visibility = visibility_from_audience_with_silence
 
-    if searchability == visibility
+    if searchability == visibility || searchability == :limited || searchability == :direct
       searchability
-    elsif [:public, :unlisted, :private].include?(searchability) && [:public, :unlisted, :private].include?(visibility)
+    elsif [:public, :unlisted, :private].include?(searchability) && [:public, :public_unlisted, :unlisted, :private].include?(visibility)
       :private
     else
       :direct

app/lib/activitypub/tag_manager.rb

@@ -217,6 +217,8 @@ class ActivityPub::TagManager
         [account_followers_url(status.account)]
       when 'direct'
         status.conversation_id.present? ? [uri_for(status.conversation)] : []
+      when 'limited'
+        ['as:Limited']
       else
         []
       end
@@ -230,6 +232,8 @@ class ActivityPub::TagManager
       [COLLECTIONS[:public]]
     when 'private', 'direct'
       [account_followers_url(account)]
+    when 'limited'
+      ['as:Limited']
     else
       []
     end