mix ash_onetime.roll_partitions (ash_onetime v0.2.0)

Creates the next batch of monthly ash_onetime_response_payloads range partitions.

mix ash_onetime.roll_partitions --repo MyApp.Repo
mix ash_onetime.roll_partitions --repo MyApp.Repo --prefix tenant_1 --months 6

Forward partition creation keeps retention bounded past the install window: without it, payloads whose response_partition falls outside the generated window route to the _default partition and are never dropped, silently defeating bounded retention. Idempotent and concurrency-safe (advisory-locked). Schedule it via AshOnetime.Oban.PartitionWorker or a cron cadence; the operator picks --months to stay ahead of their retention horizon.