Reuse document indexes in D&D validators

internal/modules/dnd/validate/npcs/source_refs/validator.go

@@ -37,10 +37,11 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 	if err := npcshape.Validate(req.Value); err != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
+	index := source.NewDocumentIndex(req.Source)
 	issues := make([]string, 0)
 	for npcIndex, npc := range req.Value.NPCs {
 		for refIndex, ref := range npc.SourceRefs {
-			if err := source.ValidateRef(req.Source, ref); err != nil {
+			if err := index.ValidateRef(ref); err != nil {
 				issues = append(issues, fmt.Sprintf("npcs[%d].source_refs[%d]: %s", npcIndex, refIndex, diagnostics.Truncate(err.Error())))
 			}
 		}