Send onboarding next steps after contract is signed

Signed candidate contracts lack onboarding context, forcing manual emails and scheduling. Deliver next steps automatically so coordinators finalize onboarding the same day.

Overview

Signed contracts should immediately trigger onboarding, not more manual work. This flow emails the new hire and records the outreach within minutes, while surfacing the event in Slack so recruiting coordinators can finalize onboarding the same day. It cuts manual follow-up and speeds new-hire readiness.