Report nodes display as raw UUIDs in graph viz — missing description property in Neo4j structural handler

Report nodes in the knowledge graph visualization display their raw UUID as the label (e.g. "d0ed41a7-291d-4eaf-97dc-e4d7ddbf890f") instead of a human-readable description. The graph viz frontend uses coalesce(n.description, n.name, n.id) to resolve labels, but the incremental sync handler for reports (onKnowledgeReportCreated in packages/graph/src/etl/incremental.ts) sets r.problemDescription but never sets r.description. Since the Report node has no description or name property, the coalesce falls through to the UUID.