Add clarifying comment to table_cell_selector transformation

Agent-Logs-Url: https://github.com/activeadmin-plugins/capybara_active_admin/sessions/7498bf2c-1012-4f45-a573-e5f8a7124f08

Co-authored-by: senid231 <8393857+senid231@users.noreply.github.com>

Author: Copilot

lib/capybara/active_admin/selectors/table.rb

@@ -32,6 +32,7 @@ def table_header_selector
         def table_cell_selector(column = nil)
           return 'td.col' if column.nil?
 
+          # Downcase, strip non-alphanumeric chars (e.g. '/'), convert spaces to '_', deduplicate '_'
           column = column.to_s.downcase.gsub(/[^a-z0-9\s]/, '').gsub(/\s+/, '_').squeeze('_')
           "td.col.col-#{column}"
         end