Improve semantic reconciliation retries

internal/framework/pipeline/producer_attempts_test.go

@@ -218,6 +218,9 @@ func TestRunProducerAttemptsUsesModuleRetryBudgetAndFallback(t *testing.T) {
 		calls := 0
 		terminal, err := runProducerAttempts(context.Background(), producerAttemptConfig{Retries: 1, Policy: DefaultValidationPolicy()}, func(_ context.Context, request producerAttemptRequest) (producerAttemptOutput, error) {
 			calls++
+			if request.Correction != nil {
+				t.Fatalf("feedback-free module retry correction = %#v, want nil", request.Correction)
+			}
 			if request.Number == 1 {
 				return producerAttemptOutput{Value: "fallback", Retry: &producerRetryDirective{}}, nil
 			}
@@ -234,6 +237,58 @@ func TestRunProducerAttemptsUsesModuleRetryBudgetAndFallback(t *testing.T) {
 		}
 	})
 
+	t.Run("feedback retry", func(t *testing.T) {
+		const (
+			defective = `{"duplicate_groups":[{"candidate_ids":[1,99],"canonical_candidate_id":1}]}`
+			guidance  = "Use only candidate IDs from the supplied candidate list. Return one complete corrected response."
+		)
+		var observed *contracts.SemanticCorrection
+		terminal, err := runProducerAttempts(context.Background(), producerAttemptConfig{Retries: 1, Policy: DefaultValidationPolicy()}, func(_ context.Context, request producerAttemptRequest) (producerAttemptOutput, error) {
+			if request.Number == 1 {
+				return producerAttemptOutput{Value: "safe fallback", Candidate: attemptCandidate(t, defective), Retry: &producerRetryDirective{CorrectionGuidance: guidance}}, nil
+			}
+			observed = request.Correction
+			return producerAttemptOutput{Value: "corrected"}, nil
+		}, approveAttempt)
+		if err != nil {
+			t.Fatalf("runProducerAttempts() error = %v", err)
+		}
+		if terminal.Action != producerTerminalAccepted || terminal.Value != "corrected" {
+			t.Fatalf("terminal = %#v, want corrected accepted value", terminal)
+		}
+		if observed == nil || string(observed.AssistantResponse) != defective || observed.UserGuidance != guidance {
+			t.Fatalf("module retry correction = %#v, want exact latest response and guidance", observed)
+		}
+		if got := attemptKinds(terminal.Provenance); !reflect.DeepEqual(got, []producerAttemptKind{producerAttemptInitial, producerAttemptModuleRetry}) {
+			t.Fatalf("attempt kinds = %v", got)
+		}
+	})
+
+	t.Run("feedback-free retry clears prior correction", func(t *testing.T) {
+		terminal, err := runProducerAttempts(context.Background(), producerAttemptConfig{Retries: 2, Policy: DefaultValidationPolicy()}, func(_ context.Context, request producerAttemptRequest) (producerAttemptOutput, error) {
+			switch request.Number {
+			case 1:
+				return producerAttemptOutput{Value: "first fallback", Candidate: attemptCandidate(t, "first defective response"), Retry: &producerRetryDirective{CorrectionGuidance: "Correct the first response."}}, nil
+			case 2:
+				if request.Correction == nil || string(request.Correction.AssistantResponse) != "first defective response" {
+					t.Fatalf("second attempt correction = %#v", request.Correction)
+				}
+				return producerAttemptOutput{Value: "second fallback", Retry: &producerRetryDirective{}}, nil
+			case 3:
+				if request.Correction != nil {
+					t.Fatalf("third attempt retained stale correction %#v", request.Correction)
+				}
+				return producerAttemptOutput{Value: "accepted"}, nil
+			default:
+				t.Fatalf("unexpected producer attempt %d", request.Number)
+				return producerAttemptOutput{}, nil
+			}
+		}, approveAttempt)
+		if err != nil || terminal.Action != producerTerminalAccepted || terminal.Value != "accepted" {
+			t.Fatalf("terminal = %#v, error = %v", terminal, err)
+		}
+	})
+
 	t.Run("fallback", func(t *testing.T) {
 		fallbackDiagnostic := contracts.ProducerDiagnostic{Disposition: contracts.DiagnosticDispositionWarning, Category: contracts.DiagnosticCategoryFallback, ReasonCode: "fallback", OccurrenceCount: 1, Samples: []contracts.DiagnosticSample{{Scope: "fallback", Message: "fallback warning"}}}
 		terminal, err := runProducerAttempts(context.Background(), producerAttemptConfig{Policy: DefaultValidationPolicy()}, func(context.Context, producerAttemptRequest) (producerAttemptOutput, error) {
@@ -248,6 +303,24 @@ func TestRunProducerAttemptsUsesModuleRetryBudgetAndFallback(t *testing.T) {
 	})
 }
 
+func TestRunProducerAttemptsRejectsModuleCorrectionWithoutModelCandidate(t *testing.T) {
+	producerCalls := 0
+	validatorCalls := 0
+	terminal, err := runProducerAttempts(context.Background(), producerAttemptConfig{Retries: 1, Policy: DefaultValidationPolicy()}, func(context.Context, producerAttemptRequest) (producerAttemptOutput, error) {
+		producerCalls++
+		return producerAttemptOutput{Value: "safe", Retry: &producerRetryDirective{CorrectionGuidance: "Return a complete corrected response."}}, nil
+	}, func(context.Context, producerAttemptOutput) (validationReport, error) {
+		validatorCalls++
+		return validationReport{}, nil
+	})
+	if err == nil || !strings.Contains(err.Error(), "requires a model candidate") {
+		t.Fatalf("runProducerAttempts() error = %v, want model-candidate contract failure", err)
+	}
+	if terminal.Action != producerTerminalFailed || producerCalls != 1 || validatorCalls != 0 {
+		t.Fatalf("terminal = %#v, producer calls = %d, validator calls = %d", terminal, producerCalls, validatorCalls)
+	}
+}
+
 func TestRunProducerAttemptsRejectsInvalidDiagnosticsWithoutRetry(t *testing.T) {
 	tests := []struct {
 		name   string