Replace tm:reason and tm:secondaryReason with a single tm:hasReason
property (937 triples). Refactor 6 flat date properties into structured
tm:uncertainBeginning/tm:uncertainEnd intervals using W3C OWL-Time,
introducing tm:FuzzyInterval as a superclass of tm:Migration,
org:Membership, tm:Relationship, tm:PersonName, and
tm:ReligionAffiliation. Output: data/graph-08.ttl (218,251 triples).
