Preserve empty smoke error messages in aggregate reports

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Dependency upgrade and PromptKit smoke review remediation
 
-Status: open; R-1 through R-4 require attention.
+Status: in progress; R-1 complete; R-2 through R-4 remain open.
 
 ## Review scope and evidence
 
@@ -34,13 +34,14 @@ modules. No test suite was run or added during this review.
 
 The completed implementation plan records earlier test runs; those completion
 markers are historical evidence, not fresh test results from this review.
-No production correction has been applied here. The preceding completed
+No production correction was applied during the review. Completion records
+below describe the subsequent remediation. The preceding completed
 request-validation review remains available in
 [Git history](https://gitea.maximumdirect.net/eric/CommandKit/src/commit/730f930b47c929fb2c59a25a75cbe2924dfc75bb/docs/roadmap/remediation.md).
 
 ## R-1: Preserve aggregate error presence when its message is empty
 
-Status: open. Priority: P2. Category: report fidelity.
+Status: complete. Priority: P2. Category: report fidelity.
 
 **Location:** [smoke_report.go](../../integrations/ckprompt/smoke_report.go),
 `smokeResultDTO` and `encodeSmokeResults`, lines 101–125.
@@ -69,6 +70,14 @@ message remains `error: ""`. Confirm the assembled aggregate still returns
 operational failure and preserves the original error through `errors.Is`.
 The appropriate focused tests and ckprompt suite pass.
 
+**Completed:** 2026-10-18. Changed the private aggregate error field to an
+optional string pointer, preserving non-nil empty messages. Extended the YAML
+projection and assembled aggregate regressions to distinguish nil, empty, and
+nonempty errors while retaining operational classification and typed cause
+identity. Both focused regressions failed before the fix and passed afterward.
+The complete ckprompt suite, including the composed consumer, passed with
+Go 1.26.8 and offline dependency resolution.
+
 ## R-2: Remove assertions about PromptKit's private smoke-test execution
 
 Status: open. Priority: P3. Category: upstream testing ownership.

integrations/ckprompt/smoke_outcome_test.go

@@ -141,7 +141,7 @@ func (err *smokeTypedError) Error() string { return err.text }
 
 func TestSmokeAggregatePreservesMultipleTypedCauses(t *testing.T) {
 	firstErr := &smokeTypedError{text: "reachability failed"}
-	secondErr := &smokeTypedError{text: "authentication failed"}
+	secondErr := &smokeTypedError{text: ""}
 	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
 		SmokeTest: func(_ context.Context, request SmokeRequest, _ struct{}, _ struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
 			var err error
@@ -162,14 +162,14 @@ func TestSmokeAggregatePreservesMultipleTypedCauses(t *testing.T) {
 	}
 	var document struct {
 		Tests []struct {
-			Kind  string `yaml:"kind"`
+			Kind  string  `yaml:"kind"`
-			Error string `yaml:"error"`
+			Error *string `yaml:"error"`
 		} `yaml:"tests"`
 	}
 	if err := yaml.Unmarshal(output.Bytes(), &document); err != nil {
 		t.Fatalf("decode aggregate errors %q: %v", output.String(), err)
 	}
-	if len(document.Tests) != 4 || document.Tests[0].Kind != string(promptkit.SmokeTestReachability) || document.Tests[0].Error != firstErr.Error() || document.Tests[1].Kind != string(promptkit.SmokeTestAuthentication) || document.Tests[1].Error != secondErr.Error() || document.Tests[2].Error != "" || document.Tests[3].Error != "" {
+	if len(document.Tests) != 4 || document.Tests[0].Kind != string(promptkit.SmokeTestReachability) || document.Tests[0].Error == nil || *document.Tests[0].Error != firstErr.Error() || document.Tests[1].Kind != string(promptkit.SmokeTestAuthentication) || document.Tests[1].Error == nil || *document.Tests[1].Error != secondErr.Error() || document.Tests[2].Error != nil || document.Tests[3].Error != nil {
 		t.Fatalf("aggregate error entries = %#v", document.Tests)
 	}
 }

integrations/ckprompt/smoke_report.go

@@ -101,7 +101,7 @@ type smokeAggregateDTO struct {
 type smokeResultDTO struct {
 	Kind   promptkit.SmokeTestKind `yaml:"kind"`
 	Report *smokeReportDTO         `yaml:"report"`
-	Error  string                  `yaml:"error,omitempty"`
+	Error  *string                 `yaml:"error,omitempty"`
 }
 
 type smokeResult struct {
@@ -122,7 +122,8 @@ func encodeSmokeResults(results []smokeResult) ([]byte, error) {
 			Report: smokeReportFromNative(result.Report),
 		}
 		if result.Err != nil {
-			entries[index].Error = result.Err.Error()
+			message := result.Err.Error()
+			entries[index].Error = &message
 		}
 	}
 	return encodePromptYAMLBytes(smokeAggregateDTO{Tests: entries})

integrations/ckprompt/smoke_report_test.go

@@ -163,6 +163,7 @@ func TestSmokeAggregateYAMLRetainsOrderErrorAndNativeReportKind(t *testing.T) {
 	encoded, err := encodeSmokeResults([]smokeResult{
 		{Kind: promptkit.SmokeTestTextInference, Report: report, Err: operationErr},
 		{Kind: promptkit.SmokeTestAuthentication},
+		{Kind: promptkit.SmokeTestStructuredOutput, Report: report, Err: errors.New("")},
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -172,7 +173,7 @@ func TestSmokeAggregateYAMLRetainsOrderErrorAndNativeReportKind(t *testing.T) {
 		t.Fatalf("decode aggregate report: %v\n%s", err, encoded)
 	}
 	tests, ok := document["tests"].([]any)
-	if !ok || len(tests) != 2 {
+	if !ok || len(tests) != 3 {
 		t.Fatalf("aggregate entries = %#v", document)
 	}
 	first := tests[0].(map[string]any)
@@ -190,6 +191,10 @@ func TestSmokeAggregateYAMLRetainsOrderErrorAndNativeReportKind(t *testing.T) {
 	if _, exists := second["error"]; exists {
 		t.Fatalf("nil error should be omitted: %#v", second)
 	}
+	third := tests[2].(map[string]any)
+	if message, exists := third["error"]; !exists || message != "" {
+		t.Fatalf("empty error message should remain present: %#v", third)
+	}
 }
 
 func containsSmokeKey(value any, want string) bool {