Internal Queued Notifications

Return queued email / webhook notification rows for the worker.

Rows are ordered by sent_at (which for a queued row is the NOW() at insert time — effectively FIFO). The worker pulls limit at a time so a burst of hundreds of exits doesn't stall delivery of newer ones.

A queued row records that the follower wanted this channel at the moment the event fanned out. Opt-in is re-checked here at delivery time: a row is only handed to the worker if the recipient still follows the bot with that channel enabled. This is the authoritative guard behind unfollow / channel-off — it suppresses even backlog that queued before the follower opted out (including rows orphaned by an unfollow that removed the follower entirely), so "I unfollowed but the emails keep coming" cannot happen regardless of how a row was queued.