First-agent onboarding and more dependable event automations

New accounts now enter first-agent onboarding when their project has no agents. The questions use the same role, company-size and referral choices as the signup survey, so people do not need to answer conflicting versions of them.
- Event automations now receive Composio V3 webhook events instead of silently dropping them.
- Editing an automation's event filters now updates its Composio trigger.
- Organizations replace workspace records; self-hosted operators should read the upgrade notes before deploying.