refactor: remove db.commit() from business services, callers use UnitOfWork (Tier 3)

backend/app/services/osint_enrichment_service.py

@@ -181,12 +181,10 @@ def get_osint_items_for_technique(
 
 
 def mark_osint_reviewed(db: Session, item_id: str) -> OsintItem | None:
-    """Mark an OSINT item as reviewed."""
+    """Mark an OSINT item as reviewed. Does not commit; caller uses UnitOfWork."""
     item = db.query(OsintItem).filter(OsintItem.id == item_id).first()
     if item:
         item.reviewed = True
-        db.commit()
-        db.refresh(item)
     return item