Add namespace and collection inventories

internal/engine/engine.go

@@ -97,6 +97,8 @@ type identityInventory interface {
 	ListBackends(context.Context) ([]string, error)
 	ListProfiles(context.Context) ([]string, error)
 	ListPrompts(context.Context) ([]domain.PromptIdentity, error)
+	ListNamespaces(context.Context, []string) ([]string, error)
+	ListCollections(context.Context) ([]configuration.CollectionIdentity, error)
 }
 
 // ListingFilterMode selects namespace membership for one identity listing.
@@ -277,6 +279,21 @@ func (e *Engine) ListPrompts(ctx context.Context, filters ...ListingFilter) ([]d
 	return filtered, nil
 }
 
+func (e *Engine) ListNamespaces(ctx context.Context, kinds []string) ([]string, error) {
+	for _, kind := range kinds {
+		switch kind {
+		case "prompt", "profile", "backend":
+		default:
+			return nil, fmt.Errorf("%w: unknown resource kind %q", usecase.ErrInvalidRequest, kind)
+		}
+	}
+	return e.listing.ListNamespaces(ctx, kinds)
+}
+
+func (e *Engine) ListCollections(ctx context.Context) ([]configuration.CollectionIdentity, error) {
+	return e.listing.ListCollections(ctx)
+}
+
 func filterIdentityList(
 	ctx context.Context,
 	filters []ListingFilter,