A weekend with no index no longer looks like a blocked source
The regulator answers a request for a daily index on a day with no publications with an access error rather than a not-found. The ingestion daemon asked for today's index and, every weekend, logged that the source had blocked us.
An alert that lies on a schedule stops being read, so ingestion now takes the most recent day from the listing of indexes that actually exist. The general policy on access errors during document retrieval was not relaxed: it still means blocked, and working around it stays prohibited.