Implement operation-time D&D NPC artifact handoff

internal/modules/dnd/extract/spells/npc_registry_wiring_test.go

@@ -84,6 +84,32 @@ func TestSpellExtractorPreservesSemanticNPCRegistryFingerprintAndPromptWiring(t
 	}
 }
 
+func TestSpellExtractorResolvesOperationNPCOverrideWithoutSingletonMetadata(t *testing.T) {
+	canonical, err := npccodec.New().Encode(registryFixture())
+	if err != nil {
+		t.Fatalf("encode NPC registry: %v", err)
+	}
+	client := &fakeSpellsLLMClient{response: extractionResponse{SpellCasts: []spellCastResponse{}}}
+	extractor := newExtractor(t, client)
+	request := extractionRequest()
+	request.References = spellNPCRegistryReference(canonical, "file:///generated.json")
+	if _, err := extractor.Extract(context.Background(), request); err != nil {
+		t.Fatalf("Extract() error = %v", err)
+	}
+	input := client.requests[0].Inputs[NPCRegistryReferenceSlot]
+	if input.Digest == "" || string(input.Content) != string(canonical) || input.OriginURI != "" {
+		t.Fatalf("operation NPC input = %#v, want generated canonical grounding without provenance", input)
+	}
+	if metadata := extractor.ManifestMetadata(); metadata["npc_registry_digest"] != nil || metadata["npc_count"] != nil {
+		t.Fatalf("singleton metadata = %#v, want no operation-varying NPC identity", metadata)
+	}
+	for _, fingerprint := range extractor.CheckpointFingerprints() {
+		if fingerprint.Name == "npc_registry" {
+			t.Fatalf("singleton fingerprints = %#v, want no operation-varying NPC identity", extractor.CheckpointFingerprints())
+		}
+	}
+}
+
 func registryFixture() dnd.NPCList {
 	return dnd.NPCList{NPCs: []dnd.NPC{{
 		ID:          identity.DeriveID("Mira Thorn"),