Add cold-start follow recommendations (#15945)

app/models/account_summary.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: account_summaries
+#
+#  account_id :bigint(8)        primary key
+#  language   :string
+#  sensitive  :boolean
+#
+
+class AccountSummary < ApplicationRecord
+  self.primary_key = :account_id
+
+  scope :safe, -> { where(sensitive: false) }
+  scope :localized, ->(locale) { where(language: locale) }
+  scope :filtered, -> { joins(arel_table.join(FollowRecommendationSuppression.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:account_id].eq(FollowRecommendationSuppression.arel_table[:account_id])).join_sources).where(FollowRecommendationSuppression.arel_table[:id].eq(nil)) }
+
+  def self.refresh
+    Scenic.database.refresh_materialized_view(table_name, concurrently: true, cascade: false)
+  end
+
+  def readonly?
+    true
+  end
+end