Implements onboarding page, fixes login redirect, adds mock data to professional directory, and includes a screenshot asset. Replit-Commit-Author: Agent Replit-Commit-Session-Id: 556aa286-edd2-4cea-8583-f4fc3cfd119b Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/81470e0d-8ae8-4335-9301-cd9a69e670fa/6009c02a-0a60-49de-bce6-3126cf528401.jpg