Strengthen validation retries and checkpoint safety

internal/modules/dnd/validate/combatturns/source_refs/validator.go

@@ -49,9 +49,10 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 		return contracts.ValidationResult{Approved: true}, nil
 	}
 	return contracts.ValidationResult{
-		Approved:   false,
-		ReasonCode: ReasonCode,
-		Message:    diagnostics.Aggregate("invalid combat turn source references", issues),
+		Approved:           false,
+		ReasonCode:         ReasonCode,
+		Message:            diagnostics.Aggregate("invalid combat turn source references", issues),
+		CorrectionGuidance: "Return combat turns whose source references identify valid transcript ranges within the supplied extraction chunk and directly support each turn.",
 	}, nil
 }
 

internal/modules/dnd/validate/combatturns/source_refs/validator_test.go

@@ -42,6 +42,9 @@ func TestValidatorRejectsInvalidSourceIdentityExistenceAndOrder(t *testing.T) {
 			if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, test.want) {
 				t.Fatalf("Validate() = %#v, %v; want source-reference rejection containing %q", result, err, test.want)
 			}
+			if err := contracts.ValidateValidationResult(result); err != nil {
+				t.Fatalf("ValidateValidationResult() error = %v for %#v", err, result)
+			}
 		})
 	}
 }