The actual "who sells honey with a .es domain" feature: search sites
by keyword — matched against page title/description/keywords/body
text via a new MySQL fulltext index on site_pages — combined with an
optional TLD filter on the domain. Results are sites ranked by number
of matching pages. Shows nothing until a filter is entered, so it
doesn't just duplicate the plain Sites browse page.
Verified against real .es data pulled in for the test (dominio ->
4 matching sites, correctly ranked and TLD-filtered).