fix: satisfy backend lint

backend/internal/service/kiro_http_helpers.go

@@ -84,7 +84,7 @@ func buildKiroRequestID(resp *http.Response) string {
 	return strings.TrimSpace(resp.Header.Get("x-amz-request-id"))
 }
 
-func isKiroInvalidModelIDBody(respBody []byte) bool {
+func isKiroInvalidModelIDBody(respBody []byte) bool { //nolint:unused // exercised by internal tests for error classification.
 	var payload struct {
 		Reason  string `json:"reason"`
 		Message string `json:"message"`

backend/internal/service/kiro_runtime.go

@@ -491,7 +491,7 @@ func buildKiroEndpoints(account *Account) []kiroEndpointConfig {
 	}
 }
 
-func buildKiroPayloadForAccount(ctx context.Context, account *Account, anthropicBody []byte, modelID, token, requestModel string, headers http.Header) ([]byte, error) {
+func buildKiroPayloadForAccount(ctx context.Context, account *Account, anthropicBody []byte, modelID, token, requestModel string, headers http.Header) ([]byte, error) { //nolint:unused // exercised by package tests as a narrow payload helper.
 	result, err := buildKiroPayloadForAccountWithRepo(ctx, nil, account, anthropicBody, modelID, token, requestModel, headers)
 	if err != nil {
 		return nil, err

backend/internal/service/kiro_websearch.go

@@ -357,11 +357,11 @@ func buildKiroWebSearchMCPRequest(query string) kiropkg.MCPRequest {
 		ID:      fmt.Sprintf("web_search_%s", kiropkg.GenerateToolUseID()),
 		JSONRPC: "2.0",
 		Method:  "tools/call",
-		Params: map[string]interface{}{
+		Params: map[string]any{
 			"name": "web_search",
-			"arguments": map[string]interface{}{
+			"arguments": map[string]any{
 				"query": query,
-				"_meta": map[string]interface{}{
+				"_meta": map[string]any{
 					"_isValid":        true,
 					"_activePath":     []string{"query"},
 					"_completedPaths": [][]string{{"query"}},