fix(go): forward binary_results_for_llm and session_log in HandlePendingToolCall RPC

ToolResult.BinaryResultsForLLM and SessionLog were dropped when building
ExternalToolTextResultForLlm in executeToolAndRespond, mirroring the same
bug fixed in Python by this PR. Binary tool outputs (e.g. images) returned
by Go tool handlers never reached the model.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SteveSandersonMS

go/session.go

@@ -1575,6 +1575,20 @@ func (s *Session) executeToolAndRespond(requestID, toolName, toolCallID string,
 	if result.Error != "" {
 		rpcResult.Error = &result.Error
 	}
+	if result.SessionLog != "" {
+		rpcResult.SessionLog = &result.SessionLog
+	}
+	for _, b := range result.BinaryResultsForLLM {
+		entry := rpc.ExternalToolTextResultForLlmBinaryResultsForLlm{
+			Data:     b.Data,
+			MIMEType: b.MIMEType,
+			Type:     rpc.ExternalToolTextResultForLlmBinaryResultsForLlmType(b.Type),
+		}
+		if b.Description != "" {
+			entry.Description = &b.Description
+		}
+		rpcResult.BinaryResultsForLlm = append(rpcResult.BinaryResultsForLlm, entry)
+	}
 	s.RPC.Tools.HandlePendingToolCall(ctx, &rpc.HandlePendingToolCallRequest{
 		RequestID: requestID,
 		Result:    rpcResult,