Move NPC registry to canonical namespace

internal/modules/dnd/extract/npcregistry/model.go

@@ -0,0 +1,15 @@
+package npcregistry
+
+type extractionResponse struct {
+	NPCs []npcResponse `json:"npcs"`
+}
+
+type npcResponse struct {
+	Name       string                 `json:"name"`
+	SourceRefs []npcSourceRefResponse `json:"source_refs"`
+}
+
+type npcSourceRefResponse struct {
+	StartUnitID int `json:"start_unit_id"`
+	EndUnitID   int `json:"end_unit_id"`
+}