ALL-963: Relay deal activity logging

completed

Priority: 0

P0 Relay sales-QA bug: no way to log call/email/meeting/note on a deal. Scope backend DealActivity scaffold + mutations/resolvers/tests and Deal detail UI. Likely split backend Talos / UI Atlas. Branch talos/all-963-deal-activity-log.

Event Timeline

created

status_change

in_progress → completed