Ground item occurrences by canonical names

assets/dnd/item-occurrences/prompts/instructions.md

@@ -3,10 +3,10 @@ in party possession established by the transcript. This is an occurrence history
 not an inventory or ledger: do not calculate balances, resolve item identity
 across records, or infer ownership that the transcript does not establish.
 
-For every occurrence, copy the exact `item_id` and `name` pair from the supplied
-item registry. Record a stated quantity as an integer and leave it null when the transcript
-does not state one. Use a concise observed item name and preserve the stated
-currency denomination.
+For every occurrence, use the supplied canonical item `name`. Record a stated
+quantity as an integer and leave it null when the transcript does not state
+one. Use a concise observed item name and preserve the stated currency
+denomination.
 
 Use `discovered` when the party learns of or encounters an item without
 establishing possession. Use `acquired` when the party or a party member gains

assets/dnd/item-occurrences/prompts/item-registry.md

@@ -1,6 +1,6 @@
 Use the supplied item registry only to ground each occurrence. Every record
-must copy one registry item's exact `id` and exact `name`; do not invent,
-rename, merge, or infer registry items. The registry is not transcript
-evidence: cite only the current transcript chunk in `source_refs`.
+must use one registry item's canonical `name`; do not invent, rename, merge,
+or infer registry items. The registry is not transcript evidence: cite only the
+current transcript chunk in `source_refs`.
 
 {{ input "item_registry" }}

assets/dnd/item-occurrences/schemas/dnd_item_occurrences_llm.v1.json

@@ -10,9 +10,8 @@
       "items": {
         "type": "object",
         "additionalProperties": false,
-        "required": ["item_id", "name", "kind", "quantity", "from", "to", "source_refs"],
+        "required": ["name", "kind", "quantity", "from", "to", "source_refs"],
         "properties": {
-          "item_id": {"type": "string"},
           "name": {"type": "string"},
           "kind": {"type": "string"},
           "quantity": {"type": ["integer", "null"]},

internal/cli/dnd_enemy_events_contract_test.go

@@ -230,7 +230,7 @@ func TestMaintainedCompleteExamplePublishesRegistryBackedEntityOccurrences(t *te
 		requiresIDs bool
 	}{
 		{promptID: npcoccurrences.PromptID, slot: "npc_registry", name: "Kesh"},
-		{promptID: itemoccurrences.PromptID, slot: "item_registry", name: "Moonblade", requiresIDs: true},
+		{promptID: itemoccurrences.PromptID, slot: "item_registry", name: "Moonblade"},
 	} {
 		requests := client.requestsFor(test.promptID)
 		if len(requests) != 2 {
@@ -321,16 +321,16 @@ func (client *enemyEventLLMClient) CompleteStructured(ctx context.Context, reque
 		} else {
 			var registry struct {
 				Items []struct {
-					ID string `json:"id"`
+					Name string `json:"name"`
 				} `json:"items"`
 			}
 			if err := json.Unmarshal(request.Inputs["item_registry"].Content, &registry); err != nil {
 				return contracts.StructuredCompletionResponse{}, fmt.Errorf("decode generated item registry: %w", err)
 			}
-			if len(registry.Items) != 1 {
+			if len(registry.Items) != 1 || registry.Items[0].Name != "Moonblade" {
 				return contracts.StructuredCompletionResponse{}, fmt.Errorf("generated item registry has %d items, want 1", len(registry.Items))
 			}
-			content = []byte(fmt.Sprintf(`{"occurrences":[{"item_id":%q,"name":"Moonblade","kind":"discovered","quantity":null,"from":null,"to":null,"source_refs":[{"start_segment":5,"end_segment":5}]}]}`, registry.Items[0].ID))
+			content = []byte(`{"occurrences":[{"name":"Moonblade","kind":"discovered","quantity":null,"from":null,"to":null,"source_refs":[{"start_segment":5,"end_segment":5}]}]}`)
 		}
 	case combat.PromptID:
 		content = []byte(`{"combat_turns":[{"actor":"Kesh","turn_kind":"turn","source_refs":[{"start_unit_id":8,"end_unit_id":8}]}]}`)
@@ -338,16 +338,16 @@ func (client *enemyEventLLMClient) CompleteStructured(ctx context.Context, reque
 		if combatScene {
 			var registry struct {
 				NPCs []struct {
-					ID string `json:"id"`
+					Name string `json:"name"`
 				} `json:"npcs"`
 			}
 			if err := json.Unmarshal(request.Inputs["npc_registry"].Content, &registry); err != nil {
 				return contracts.StructuredCompletionResponse{}, fmt.Errorf("decode generated NPC registry: %w", err)
 			}
-			if len(registry.NPCs) == 0 {
+			if len(registry.NPCs) == 0 || registry.NPCs[0].Name != "Kesh" {
 				return contracts.StructuredCompletionResponse{}, fmt.Errorf("generated NPC registry has no NPCs")
 			}
-			content = []byte(fmt.Sprintf(`{"occurrences":[{"npc_id":%q,"name":"Kesh","kind":"combat_opponent","source_refs":[{"start_unit_id":7,"end_unit_id":7}]}]}`, registry.NPCs[0].ID))
+			content = []byte(`{"occurrences":[{"name":"Kesh","kind":"combat_opponent","source_refs":[{"start_unit_id":7,"end_unit_id":7}]}]}`)
 		} else {
 			content = []byte(`{"occurrences":[]}`)
 		}

internal/modules/dnd/extract/itemoccurrences/canonicalize.go

@@ -22,9 +22,11 @@ func canonicalizeResponse(response *extractionResponse, order shared.SourceRefOr
 	}
 	ordered := make([]orderedItemOccurrenceResponse, len(response.Occurrences))
 	for index := range response.Occurrences {
-		if err := validateRegistryPair(index, response.Occurrences[index], registry); err != nil {
-			return err
+		canonical, found := registry.Lookup(response.Occurrences[index].Name)
+		if !found {
+			return fmt.Errorf("occurrences[%d].name is not in the item registry", index)
 		}
+		response.Occurrences[index].Name = canonical.Name
 		earliest, hasEvidence := canonicalizeItemOccurrence(&response.Occurrences[index], order, sourceID)
 		ordered[index] = orderedItemOccurrenceResponse{
 			value:       response.Occurrences[index],
@@ -56,26 +58,19 @@ func canonicalizeItemOccurrence(occurrence *itemOccurrenceResponse, order shared
 	return order.EarliestValid(refs)
 }
 
-func validateRegistryPair(index int, occurrence itemOccurrenceResponse, registry *itemregistry.Registry) error {
-	item, found := registry.LookupID(occurrence.ItemID)
-	if !found {
-		return fmt.Errorf("occurrences[%d].item_id is not in the item registry", index)
-	}
-	if item.Name != occurrence.Name {
-		return fmt.Errorf("occurrences[%d].name does not match item_id", index)
-	}
-	return nil
-}
-
-func canonicalItemOccurrenceList(response extractionResponse, sourceID string) dnd.ItemOccurrenceList {
+func canonicalItemOccurrenceList(response extractionResponse, sourceID string, registry *itemregistry.Registry) (dnd.ItemOccurrenceList, error) {
 	if response.Occurrences == nil {
-		return dnd.ItemOccurrenceList{}
+		return dnd.ItemOccurrenceList{}, nil
 	}
 	occurrences := make([]dnd.ItemOccurrence, 0, len(response.Occurrences))
-	for _, occurrence := range response.Occurrences {
+	for index, occurrence := range response.Occurrences {
+		item, found := registry.Lookup(occurrence.Name)
+		if !found {
+			return dnd.ItemOccurrenceList{}, fmt.Errorf("occurrences[%d].name is not in the item registry", index)
+		}
 		occurrences = append(occurrences, dnd.ItemOccurrence{
-			ItemID:     occurrence.ItemID,
-			Name:       occurrence.Name,
+			ItemID:     item.ID,
+			Name:       item.Name,
 			Kind:       dnd.ItemOccurrenceKind(occurrence.Kind),
 			Quantity:   cloneQuantity(occurrence.Quantity),
 			From:       occurrence.From,
@@ -83,7 +78,7 @@ func canonicalItemOccurrenceList(response extractionResponse, sourceID string) d
 			SourceRefs: itemOccurrenceSourceRefs(occurrence.SourceRefs, sourceID),
 		})
 	}
-	return dnd.ItemOccurrenceList{Occurrences: occurrences}
+	return dnd.ItemOccurrenceList{Occurrences: occurrences}, nil
 }
 
 func itemOccurrenceSourceRefs(refs []itemOccurrenceSourceRefResponse, sourceID string) []source.SourceRef {

internal/modules/dnd/extract/itemoccurrences/extractor.go

@@ -20,7 +20,7 @@ const (
 	ItemRegistryMaxBytes      = itemregistry.MaxBytes
 )
 
-const mappingPolicy = "dnd.item_occurrences.extract_mapping.v1"
+const mappingPolicy = "dnd.item_occurrences.extract_mapping.v2"
 
 var requiredCapabilities = []string{
 	"chunks",
@@ -164,7 +164,11 @@ func (e *Extractor) Extract(ctx context.Context, req contracts.TypedExtractionRe
 	if err := canonicalizeResponse(&response, order, req.Source.ID, registry); err != nil {
 		return contracts.TypedExtractionResult[dnd.ItemOccurrenceList]{}, extractorErrorf("map item occurrence response: %w", err)
 	}
-	return contracts.TypedExtractionResult[dnd.ItemOccurrenceList]{Value: canonicalItemOccurrenceList(response, req.Source.ID)}, nil
+	value, err := canonicalItemOccurrenceList(response, req.Source.ID, registry)
+	if err != nil {
+		return contracts.TypedExtractionResult[dnd.ItemOccurrenceList]{}, extractorErrorf("resolve canonical item occurrence names: %w", err)
+	}
+	return contracts.TypedExtractionResult[dnd.ItemOccurrenceList]{Value: value}, nil
 }
 
 func ModuleSpec() pipeline.ModuleSpec {

internal/modules/dnd/extract/itemoccurrences/extractor_test.go

@@ -12,7 +12,7 @@ import (
 func TestExtractGroundsOccurrencesInRequiredRegistry(t *testing.T) {
 	id := itemidentity.DeriveID("Torch")
 	client := &fakeItemOccurrencesLLMClient{response: extractionResponse{Occurrences: []itemOccurrenceResponse{
-		{ItemID: id, Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
+		{Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
 	}}}
 	req := extractionRequest()
 	req.References = itemRegistryReferences(t)
@@ -24,55 +24,38 @@ func TestExtractGroundsOccurrencesInRequiredRegistry(t *testing.T) {
 		t.Fatalf("occurrences = %#v", result.Value.Occurrences)
 	}
 	input := client.requests[0].Inputs[ItemRegistryReferenceSlot]
-	if input.Name != ItemRegistryReferenceSlot || string(input.Content) == "" {
-		t.Fatalf("registry prompt input = %#v", input)
+	if input.Name != ItemRegistryReferenceSlot || string(input.Content) != `{"items":[{"name":"Torch"}]}` || strings.Contains(string(input.Content), "item:sha256:") {
+		t.Fatalf("registry prompt input = %#v, want names-only projection", input)
 	}
 }
 
-func TestExtractRejectsInvalidRegistryPairs(t *testing.T) {
-	id := itemidentity.DeriveID("Torch")
-	for _, test := range []struct {
-		name       string
-		occurrence itemOccurrenceResponse
-		wantError  string
-	}{
-		{
-			name:       "unknown item ID",
-			occurrence: itemOccurrenceResponse{ItemID: "unknown", Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
-			wantError:  "occurrences[0].item_id is not in the item registry",
-		},
-		{
-			name:       "mismatched item name",
-			occurrence: itemOccurrenceResponse{ItemID: id, Name: "Lantern", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
-			wantError:  "occurrences[0].name does not match item_id",
-		},
-	} {
-		t.Run(test.name, func(t *testing.T) {
-			client := &fakeItemOccurrencesLLMClient{response: extractionResponse{Occurrences: []itemOccurrenceResponse{test.occurrence}}}
-			req := extractionRequest()
-			req.References = itemRegistryReferences(t)
-			result, err := newExtractor(t, client, req.References).Extract(context.Background(), req)
-			if err == nil || !strings.Contains(err.Error(), test.wantError) {
-				t.Fatalf("Extract() error = %v, want %q", err, test.wantError)
-			}
-			if len(result.Value.Occurrences) != 0 {
-				t.Fatalf("Extract() returned partial occurrences: %#v", result.Value.Occurrences)
-			}
-		})
-	}
-}
-
-func TestExtractRejectsResponseWithInvalidRegistryPairAfterValidOccurrence(t *testing.T) {
+func TestExtractCanonicalizesComparisonEquivalentNames(t *testing.T) {
 	id := itemidentity.DeriveID("Torch")
 	client := &fakeItemOccurrencesLLMClient{response: extractionResponse{Occurrences: []itemOccurrenceResponse{
-		{ItemID: id, Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
-		{ItemID: "unknown", Name: "Unknown", Kind: "lost", From: "party", SourceRefs: responseRefs(2, 2)},
+		{Name: "  tORCH ", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
 	}}}
 	req := extractionRequest()
 	req.References = itemRegistryReferences(t)
 	result, err := newExtractor(t, client, req.References).Extract(context.Background(), req)
-	if err == nil || !strings.Contains(err.Error(), "occurrences[1].item_id") {
-		t.Fatalf("Extract() error = %v, want occurrence index and item ID", err)
+	if err != nil {
+		t.Fatal(err)
+	}
+	occurrence := result.Value.Occurrences[0]
+	if occurrence.ItemID != id || occurrence.Name != "Torch" {
+		t.Fatalf("canonical occurrence = %#v", occurrence)
+	}
+}
+
+func TestExtractRejectsUnknownNameAfterValidOccurrence(t *testing.T) {
+	client := &fakeItemOccurrencesLLMClient{response: extractionResponse{Occurrences: []itemOccurrenceResponse{
+		{Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)},
+		{Name: "Unknown", Kind: "lost", From: "party", SourceRefs: responseRefs(2, 2)},
+	}}}
+	req := extractionRequest()
+	req.References = itemRegistryReferences(t)
+	result, err := newExtractor(t, client, req.References).Extract(context.Background(), req)
+	if err == nil || !strings.Contains(err.Error(), "occurrences[1].name is not in the item registry") {
+		t.Fatalf("Extract() error = %v, want occurrence index and unknown name", err)
 	}
 	if len(result.Value.Occurrences) != 0 {
 		t.Fatalf("Extract() returned partial occurrences: %#v", result.Value.Occurrences)
@@ -86,9 +69,36 @@ func TestExtractRequiresItemRegistry(t *testing.T) {
 	}
 }
 
+func TestExtractAcceptsOnlyEmptyResponseForEmptyRegistry(t *testing.T) {
+	references := emptyItemRegistryReferences(t)
+	for _, test := range []struct {
+		name     string
+		response extractionResponse
+		wantErr  bool
+	}{
+		{name: "empty", response: extractionResponse{Occurrences: []itemOccurrenceResponse{}}},
+		{name: "selection", response: extractionResponse{Occurrences: []itemOccurrenceResponse{{Name: "Torch", Kind: "lost", From: "party", SourceRefs: responseRefs(1, 1)}}}, wantErr: true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			client := &fakeItemOccurrencesLLMClient{response: test.response}
+			req := extractionRequest()
+			req.References = references
+			result, err := newExtractor(t, client, references).Extract(context.Background(), req)
+			if test.wantErr {
+				if err == nil || !strings.Contains(err.Error(), "name is not in the item registry") || len(result.Value.Occurrences) != 0 {
+					t.Fatalf("Extract() = %#v, %v; want no accepted occurrences", result, err)
+				}
+				return
+			}
+			if err != nil || result.Value.Occurrences == nil || len(result.Value.Occurrences) != 0 {
+				t.Fatalf("Extract() = %#v, %v; want present empty occurrences", result, err)
+			}
+		})
+	}
+}
+
 func TestExtractPreservesNullableFields(t *testing.T) {
-	id := itemidentity.DeriveID("Torch")
-	client := &fakeItemOccurrencesLLMClient{content: []byte(`{"occurrences":[{"item_id":"` + id + `","name":"Torch","kind":"discovered","quantity":null,"from":null,"to":null,"source_refs":[{"start_segment":1,"end_segment":1}]}]}`)}
+	client := &fakeItemOccurrencesLLMClient{content: []byte(`{"occurrences":[{"name":"Torch","kind":"discovered","quantity":null,"from":null,"to":null,"source_refs":[{"start_segment":1,"end_segment":1}]}]}`)}
 	req := extractionRequest()
 	req.References = itemRegistryReferences(t)
 	result, err := newExtractor(t, client, req.References).Extract(context.Background(), req)

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

@@ -5,7 +5,6 @@ type extractionResponse struct {
 }
 
 type itemOccurrenceResponse struct {
-	ItemID     string                            `json:"item_id"`
 	Name       string                            `json:"name"`
 	Kind       string                            `json:"kind"`
 	Quantity   *int                              `json:"quantity,omitempty"`

internal/modules/dnd/extract/itemoccurrences/prompt_assets_test.go

@@ -34,7 +34,7 @@ func TestPromptAssetsPrepareItemOccurrencePrompt(t *testing.T) {
 			"players":       promptkit.Inline("item-occurrence-player"),
 			"party":         promptkit.Inline(" "),
 			"glossary":      promptkit.Inline(" "),
-			"item_registry": promptkit.Inline(`{"items":[{"id":"item:sha256:test","name":"Torch"}]}`),
+			"item_registry": promptkit.Inline(`{"items":[{"name":"Torch"}]}`),
 		},
 	})
 	if err != nil {

internal/modules/dnd/extract/itemoccurrences/registry_test.go

@@ -21,6 +21,15 @@ func itemRegistryReferences(t *testing.T) contracts.ReferenceSet {
 	return contracts.ReferenceSet{Slots: map[string]contracts.ResolvedReferenceSlot{ItemRegistryReferenceSlot: {Slot: contracts.ReferenceSlot{Name: ItemRegistryReferenceSlot}, Items: []contracts.ReferenceItem{{SlotName: ItemRegistryReferenceSlot, Content: content, MediaType: "application/json", ArtifactKind: dnd.ItemRegistryKind}}}}}
 }
 
+func emptyItemRegistryReferences(t *testing.T) contracts.ReferenceSet {
+	t.Helper()
+	content, err := itemcodec.New().Encode(dnd.ItemRegistry{Items: []dnd.Item{}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return contracts.ReferenceSet{Slots: map[string]contracts.ResolvedReferenceSlot{ItemRegistryReferenceSlot: {Slot: contracts.ReferenceSlot{Name: ItemRegistryReferenceSlot}, Items: []contracts.ReferenceItem{{SlotName: ItemRegistryReferenceSlot, Content: content, MediaType: "application/json", ArtifactKind: dnd.ItemRegistryKind}}}}}
+}
+
 func testSourceRefs() []source.SourceRef {
 	return []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 1, EndUnitID: 1}}
 }

internal/modules/dnd/extract/itemoccurrences/schema_test.go

@@ -19,11 +19,11 @@ func TestResponseSchemaIsStrictlyStructuralAndPrivate(t *testing.T) {
 	}
 	valid := map[string]any{"occurrences": []any{
 		map[string]any{
-			"item_id": "item:sha256:test", "name": "", "kind": "unsupported", "quantity": 0, "from": "party", "to": "Party",
+			"name": "", "kind": "unsupported", "quantity": 0, "from": "party", "to": "Party",
 			"source_refs": []any{map[string]any{"start_segment": 0, "end_segment": -1}},
 		},
 		map[string]any{
-			"item_id": "item:sha256:test", "name": "Hidden Cache", "kind": "discovered", "quantity": nil, "from": nil, "to": nil,
+			"name": "Hidden Cache", "kind": "discovered", "quantity": nil, "from": nil, "to": nil,
 			"source_refs": []any{map[string]any{"start_segment": 1, "end_segment": 1}},
 		},
 	}}
@@ -41,6 +41,7 @@ func TestResponseSchemaIsStrictlyStructuralAndPrivate(t *testing.T) {
 		{"missing occurrences", map[string]any{}},
 		{"missing occurrence name", map[string]any{"occurrences": []any{withoutField(responseOccurrence(), "name")}}},
 		{"missing nullable field", map[string]any{"occurrences": []any{withoutField(responseOccurrence(), "quantity")}}},
+		{"opaque item identifier", map[string]any{"occurrences": []any{withField(responseOccurrence(), "item_id", "item:sha256:opaque")}}},
 		{"unknown occurrence field", map[string]any{"occurrences": []any{withField(responseOccurrence(), "extra", true)}}},
 		{"unknown reference field", map[string]any{"occurrences": []any{withField(responseOccurrence(), "source_refs", []any{map[string]any{"start_segment": 1, "end_segment": 1, "extra": true}})}}},
 		{"noninteger range", map[string]any{"occurrences": []any{withField(responseOccurrence(), "source_refs", []any{map[string]any{"start_segment": 1.5, "end_segment": 1}})}}},
@@ -68,7 +69,7 @@ func TestResponseSchemaIsStrictlyStructuralAndPrivate(t *testing.T) {
 
 func responseOccurrence() map[string]any {
 	return map[string]any{
-		"item_id": "item:sha256:test", "name": "Ring", "kind": "acquired", "quantity": nil, "from": nil, "to": "party", "source_refs": []any{},
+		"name": "Ring", "kind": "acquired", "quantity": nil, "from": nil, "to": "party", "source_refs": []any{},
 	}
 }
 

internal/modules/dnd/items/registry/registry.go

@@ -185,7 +185,7 @@ func (r *Registry) Digest() string {
 	return r.digest
 }
 
-// ProjectionDigest returns the SHA-256 digest of the exact ID/name prompt
+// ProjectionDigest returns the SHA-256 digest of the exact names-only prompt
 // projection, including for an unbound or empty registry.
 func (r *Registry) ProjectionDigest() string {
 	if r == nil {
@@ -202,8 +202,8 @@ func (r *Registry) Count() int {
 	return len(r.list.Items)
 }
 
-// PromptInput returns the ordered ID/name registry projection as a content-safe
-// prompt input. Evidence and reference provenance are omitted.
+// PromptInput returns the ordered names-only registry projection as a
+// content-safe prompt input. Durable IDs, evidence, and provenance are omitted.
 func (r *Registry) PromptInput() contracts.LLMInputMaterial {
 	if r == nil {
 		return contracts.LLMInputMaterial{}
@@ -242,7 +242,6 @@ func semanticDigest(content []byte) string {
 }
 
 type projectedItem struct {
-	ID   string `json:"id"`
 	Name string `json:"name"`
 }
 
@@ -253,7 +252,7 @@ type projectedItemRegistry struct {
 func promptProjection(list dnd.ItemRegistry) ([]byte, error) {
 	projection := projectedItemRegistry{Items: make([]projectedItem, len(list.Items))}
 	for index, item := range list.Items {
-		projection.Items[index] = projectedItem{ID: item.ID, Name: item.Name}
+		projection.Items[index] = projectedItem{Name: item.Name}
 	}
 	return json.Marshal(projection)
 }

internal/modules/dnd/items/registry/registry_test.go

@@ -25,16 +25,16 @@ func TestResolveUnboundRegistryHasExactEmptyProjection(t *testing.T) {
 	}
 }
 
-func TestResolveProjectsOrderedIDsAndNamesWithoutEvidence(t *testing.T) {
+func TestResolveProjectsOrderedNamesWithoutEvidence(t *testing.T) {
 	registry := resolveRegistry(t, fixture())
 	if !registry.Bound() || registry.Digest() == "" || registry.Count() != 2 {
 		t.Fatalf("registry identity = bound %t digest %q count %d", registry.Bound(), registry.Digest(), registry.Count())
 	}
-	want := `{"items":[{"id":"` + identity.DeriveID("Silver Key") + `","name":"Silver Key"},{"id":"` + identity.DeriveID("Healer's Kit") + `","name":"Healer's Kit"}]}`
+	want := `{"items":[{"name":"Silver Key"},{"name":"Healer's Kit"}]}`
 	if got := string(registry.PromptInput().Content); got != want {
 		t.Fatalf("prompt projection = %s, want %s", got, want)
 	}
-	for _, forbidden := range []string{"source_refs", "source_id", "session-alpha"} {
+	for _, forbidden := range []string{"item:sha256:", "source_refs", "source_id", "session-alpha"} {
 		if strings.Contains(string(registry.PromptInput().Content), forbidden) {
 			t.Fatalf("projection leaked %q: %s", forbidden, registry.PromptInput().Content)
 		}
@@ -52,6 +52,9 @@ func TestRegistryAccessorsAndLookupsAreDefensive(t *testing.T) {
 	if item, ok := registry.LookupID(identity.DeriveID("Healer's Kit")); !ok || item.Name != "Healer's Kit" {
 		t.Fatalf("LookupID() = %#v, %t", item, ok)
 	}
+	if _, ok := registry.Lookup("Unknown Item"); ok {
+		t.Fatal("Lookup() accepted an unknown item")
+	}
 
 	items := registry.Items()
 	items[0].Name = "changed"