To improve the traceability of XP logs and support a more reliable audit trail, we should add an event_id column to the XpLogs table. This will enable direct linkage between XP logs and the originating events in the Outbox, improving data integrity and debugging.

• Add a nullable event_id column to the XpLogs table. This should be just a numeric value without FK constraint due to the partitioned natured of the outbox
• Backfill existing XpLogs where a corresponding event exists and can be matched reliably (optional)
• Update XP logging logic to record the event_id where applicable
• Add test coverage for new associations
• Include migration script