Invitation controls and a new model lineup

What changed

• Revoking an invitation now closes every open link sent to that candidate. The row says Revoked, and Resend sends the candidate a fresh link.
• Recruiters can hover a skill score in candidate review to see why it was given. Signing in from a battle, profile, or recruiting page that needs an account now brings you back to that page.
• The assessment model picker has a new lineup, chosen using published benchmarks and our own grading of assessment tasks. Agentic+ adds frontier models that Agentic questions do not offer.