Add group Feature catalog content

What does this MR do and why?

Stacked MRs (2 of 3). Blocked by !261972 (merged) and independent of !261974 (merged). Whichever of this MR and !261974 (merged) merges second needs locale/gitlab.pot regenerated.

See parent MR description for context: !261972 (merged)

Adds the group panel's Explore page content: 31 nav items and 6 capabilities. The drift spec's group coverage check is no longer pending.

Adding the content found three nav items the current Feature catalog labels Free although they need a paid plan, so they get tiers:

• Value stream analytics: Premium (cycle_analytics_for_groups)
• Governance: Premium (ai_chat)
• CI/CD analytics: Ultimate (group_ci_cd_analytics_releases). It moves to Premium once Premium pipeline analytics (group_ci_cd_analytics_pipelines_ff) ships.

References

• #632720
• #631003

Screenshots or screen recordings

Not applicable: the only visible change is the tier badges in the existing modal; see validation step 1.

How to set up and validate locally

1. Visit a group, open the Feature catalog from the sidebar, and check the tier badges: Value stream analytics and Governance show Premium, CI/CD analytics shows Ultimate. On master, all three show as Free.

2. In the Rails console, print the group Explore pages:

   catalog = Onboarding::FeatureLibrary::Catalog
   %i[self_managed saas].each do |deployment|
     catalog.explore_pages(panel: :group, deployment: deployment).each do |tier, page|
       puts "\n== group / #{deployment} / #{tier}"
       puts "Highlights: #{page.highlights.map(&:translated_title).join(', ')}"
       puts "Credits:    #{page.credits.map(&:translated_title).join(', ')}"
       puts "New:        #{page.new_items.map { |i| "#{i.translated_title} (#{i.tier})" }.join(', ')}"
       page.enhanced_items.each { |e| puts "Enhanced:   #{e.nav_item.translated_title} [#{e.tier}] #{e.text}" }
     end
   end

3. Check the output:

   • The Ultimate page lists every Premium item plus the Ultimate ones.
   • Highlights differ per page; credits (GitLab Duo Agent Platform, Secrets manager) appear on both.
   • Credentials, Contribution analytics, Members and Runners only appear in the saas blocks.
   • Merge requests is missing from the Premium pages because the Merge controls highlight covers it.
   • Each enhancement shows the tier its text describes, for example Labels is [premium] on the Ultimate page.

MR acceptance checklist

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