What's new
- Added targeted database indexes for tenant-scoped message timelines, channel-scoped webhook timelines, and responder-run conversation history.
Security and operations
- A live index preflight now documents row counts, related existing indexes, and EXPLAIN evidence for the BORD-718 hot paths.
- The first BORD-718 slice intentionally avoids near-duplicate indexes where live EXPLAIN already shows adequate coverage.
- The migration uses concurrent index creation to reduce write-lock risk on hot tables during rollout.
- This reduces predictable scaling risk on high-volume webhook and inbox history paths without changing application behavior.