Allow operators to select a Redis logical database index via the
REDIS_DB environment variable. Without this, the BullMQ queue and the
@adonisjs/transmit Redis transport both implicitly used db 0, causing
key collisions when sharing a Redis instance across multiple services
or environments.
REDIS_DB is added to the env schema as an optional number; both
config/queue.ts and config/transmit.ts fall back to db 0 when unset,
preserving existing behavior.
John Onysko
Jake Turner