## Summary
Correctness and performance fixes for deployments that split run data
across more than one database. Single-database / self-hosted deployments
are unaffected (they collapse to a single read/write path).
- **Batches list (dashboard):** for some organizations the Batches list
could hide older batches or show them out of order. It now orders and
paginates by creation time (with the id as a stable tiebreak), so every
batch appears exactly once, newest first. The pagination cursor format
changes; older in-flight cursors simply restart from the first page.
- **Reads:** waitpoint and snapshot lookups that are keyed by a single
run now read only the database that holds that run instead of querying
both, removing redundant queries on hot paths (unblock, snapshot reads).
- **Writes:** environment-scoped writes with no owning run (standalone
wait tokens, waitpoint tags, idempotency-key resets) now land in the
same database as that environment's runs, rather than defaulting to the
other one. An idempotency-key reset also falls back to the other
database when it matches nothing, so a reset still clears the key
wherever the run actually lives.
## Notes
Verified end-to-end against multi-database setups: run-keyed reads and
env-scoped writes land on the correct database with no cross-database
writes, and the batches list surfaces every batch in creation order. New
tests cover the batches ordering/reachability and the write-residency
routing.
Daniel Sutton
821972176d