Mark a donation as consumed on the upstream queue so subsequent
getMostRecentDonation() calls advance past it. Invoked for
every peeked donation, regardless of whether it clears the min
threshold.
Peek the next donation from an external queue (e.g. an overlay
context provider). Called on every tick; return null to
short-circuit to the idle-check interval.
Minimum donation amount (dollars) required to show an alert. Donations below this threshold are silently consumed off the upstream queue (so the loop doesn't re-check them) but never surfaced to the caller.
Params for useAlertsQueue.