bingo: build the card from chosen providers

Let visitors tick providers (Yandex, IXcellerate, RTK-DC, Sber, …) and
get the usual 5×5 card made of only those providers' datacenters, first
25 in ranking order, with lines scored as normal. A selection with fewer
than 25 sites leaves the rest of the card empty, so the card is always
5×5. Each provider chip shows crossed/total for the current view.

Datacenters get a provider slug, backfilled from the free-text operator,
guessed for new rows and editable in the admin. Filtered URLs are
noindex with canonical to the plain card.

Assisted-by: Claude:opus-5

lib/bingo_admin.rb

@@ -3,7 +3,7 @@ require 'uri'
 # /admin/bingo/* on asxp.io: edit the card and record incidents for BingoWeb.
 # Registered into AsxpioWeb, so AdminAuth (HTTP Basic) and CSRF apply.
 module BingoAdmin
-  DC_TEXT = %w[name_ru name_en name_uk city_ru city_en city_uk operator mw mw_type status
+  DC_TEXT = %w[name_ru name_en name_uk city_ru city_en city_uk operator provider mw mw_type status
                photo_credit photo_source_url info_url about_ru about_en about_uk].freeze
 
   module Helpers
@@ -25,6 +25,7 @@ module BingoAdmin
       dc.year   = params[:year].to_s =~ /\A\d{4}\z/ ? params[:year].to_i : nil
       dc.status  = 'operational' unless Bingo::STATUSES.include?(dc.status)
       dc.mw_type = nil unless Bingo::MW_TYPES.include?(dc.mw_type)
+      dc.provider = nil unless Bingo::PROVIDERS.key?(dc.provider)
       errs = []
       errs << 'Name (ru), city (ru) and operator are required' if [dc.name_ru, dc.city_ru, dc.operator].any?(&:nil?)
       errs << 'URLs must be http(s)' unless [dc.photo_source_url, dc.info_url].all? { |u| http_url?(u.to_s) }