List Gauntlet-curated vaults

Returns identification-only rows for every Gauntlet vault the indexer knows about, ordered most-recent-first. Use /{vault_id} for current metrics, /{vault_id}/definition for the full vault definition, /{vault_id}/timeseries for history.

Cursor-paginated, but the default page size is the cap so most callers don't need to think about it — pass meta.next_cursor back as ?next= only if the result exceeds 1000 vaults.