Reuse credential discovery and diagnostic redactors

internal/framework/proposal_generation/generate.go

@@ -99,24 +99,6 @@ func GenerateCandidates(ctx context.Context, req Request) (Result, error) {
 		stage = stagename.ProposalGeneration(req.ModuleInstance, sectionIndexPtr(req.Section))
 	}
 
-	var writer InteractionDiagnosticsWriter
-	if req.DiagnosticsWriter != nil {
-		writer = req.DiagnosticsWriter
-	} else if strings.TrimSpace(req.DiagnosticsDir) != "" {
-		var secrets []string
-		if source, ok := req.LLMClient.(interface {
-			ConfiguredSecrets(context.Context) []string
-		}); ok {
-			secrets = source.ConfiguredSecrets(ctx)
-		}
-		writer = diagnosticsWriterAdapter{
-			writer: llm.NewDiagnosticsWriter(
-				filepath.Join(req.DiagnosticsDir, req.ModuleInstance),
-				secrets,
-			),
-		}
-	}
-
 	var (
 		response   StructuredCorrectionSet
 		completion contracts.StructuredCompletionResponse
@@ -153,6 +135,24 @@ func GenerateCandidates(ctx context.Context, req Request) (Result, error) {
 	}
 	requestMetadata["response_schema"] = responseschema.MustLookup(responseschema.CorrectionSetKey).DiagnosticsMap()
 
+	var writer InteractionDiagnosticsWriter
+	if req.DiagnosticsWriter != nil {
+		writer = req.DiagnosticsWriter
+	} else if strings.TrimSpace(req.DiagnosticsDir) != "" {
+		var secrets []string
+		if source, ok := req.LLMClient.(interface {
+			ConfiguredSecrets(context.Context) []string
+		}); ok {
+			secrets = source.ConfiguredSecrets(ctx)
+		}
+		writer = diagnosticsWriterAdapter{
+			writer: llm.NewDiagnosticsWriter(
+				filepath.Join(req.DiagnosticsDir, req.ModuleInstance),
+				secrets,
+			),
+		}
+	}
+
 	if writer != nil {
 		var diagnosticErr error
 		artifacts, diagnosticErr = writer.WriteInteraction(