Oban worker that runs a single subscriber's handle_event/3 for one
outbox event.
The dispatcher enqueues one job per (event, subscriber) pair so each subscriber's failures and retries are isolated.
Args:
"event_id"— UUID of the row inoutbox_events"subscriber"— the subscriber module name as a string
Return-value mapping (Oban semantics):
:ok→ job completes{:error, reason}→ Oban retries with exponential backoff- raised exception → Oban retries with exponential backoff
- unknown subscriber module → discarded with a clear error
- outbox event row missing → discarded with a clear error