Reverse zones: list other views' addresses, clearer wording

The zone page and jarl zone show list the addresses only other views'
records use (ptr_other_views_list), with the name each would get and the
view it comes from, and say plainly that they aren't missing here. The
page's button reads 'Add PTR records for them in view X'. zone show
lists the missing PTRs too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/api.md

@@ -215,7 +215,10 @@ A reverse zone created without a view goes to the private view whose
 records use its addresses. Zones come back with `prefix` (reverse zones:
 the network), `ptr_missing` (addresses in it that the view's A and AAAA
 records use, without a PTR record) and `ptr_other_views` (addresses in it
-without a PTR record that only other views' records use; not missing).
+without a PTR record that only other views' records use; not missing),
+with the first 25 of each in `ptr_missing_list` and
+`ptr_other_views_list` (`address`, `name`, `target`, and `from`, the view
+the name comes from).
 
 `/serials` and `/delegation` send DNS queries from the server, and only
 when called ([operations.md](operations.md#checking-name-servers-and-the-delegation)).