Persist diagnostics in reusable pipeline state

internal/framework/pipeline/runner_extract_handoff_test.go

@@ -158,6 +158,13 @@ func TestRunnerContinuesFromFreshAndReusedExtractResults(t *testing.T) {
 		return erasedTypedResult{
 			Value:    typedValueForLane(0, request.Chunk.Index),
 			Warnings: []contracts.Warning{{Scope: "extract", ReasonCode: "observed", Message: "accepted extract"}},
+			Diagnostics: []contracts.ProducerDiagnostic{{
+				Disposition:     contracts.DiagnosticDispositionObservation,
+				Category:        contracts.DiagnosticCategoryNormalization,
+				ReasonCode:      "accepted_extract_normalized",
+				OccurrenceCount: 1,
+				Samples:         []contracts.DiagnosticSample{{Scope: "extract", Message: "accepted extract"}},
+			}},
 		}, nil
 	})
 
@@ -209,6 +216,9 @@ func TestRunnerContinuesFromFreshAndReusedExtractResults(t *testing.T) {
 	if !reflect.DeepEqual(reused.Warnings, fresh.Warnings) {
 		t.Fatalf("reused warnings = %#v, want fresh warnings %#v", reused.Warnings, fresh.Warnings)
 	}
+	if !reflect.DeepEqual(reused.Diagnostics, fresh.Diagnostics) {
+		t.Fatalf("reused diagnostics = %#v, want fresh diagnostics %#v", reused.Diagnostics, fresh.Diagnostics)
+	}
 }
 
 func TestRunnerPromotesOnlyAcceptedExtractRetryWarnings(t *testing.T) {