Classify historical creation attribution without inventing missing detail

Historical parent records can sometimes be classified without loading child submissions or backfilling rows. Prefer the canonical creation-attribution field. If it is absent, map a denormalized external-source field together with the recorded creator; otherwise return legacy or unknown. Keep one rule table shared by the in-memory display and generated SQL so the two paths cannot drift.

Some automated and human-created records can share an external-source value, making creator identity necessary for disambiguation. If older records do not contain enough information to separate two creation channels, preserve that ambiguity rather than inventing a historical classification.