fix(worker): include stdout in error messages when Claude command fails

Auth errors like "OAuth token has expired" were lost because Claude writes
them to stdout, not stderr. The error message only showed kubectl's generic
"command terminated with exit code 1". Now includes both stdout and stderr
in the error, making failures immediately diagnosable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/adapter/codeagent/claudecode/adapter.go

@@ -162,6 +162,8 @@ func (a *Adapter) Execute(ctx context.Context, req *domain.AgentRequest, handler
 	}
 
 	// Determine exit code and error
+	stdoutStr := finalOutput.String()
+	stderrStr := stderrOutput.String()
 	if cmdErr != nil {
 		if exitErr, ok := cmdErr.(*exec.ExitError); ok {
 			result.ExitCode = exitErr.ExitCode()
@@ -169,17 +171,17 @@ func (a *Adapter) Execute(ctx context.Context, req *domain.AgentRequest, handler
 			result.ExitCode = 1
 			result.Error = cmdErr
 		}
-		// Include stderr and troubleshooting help in error
+		// Include stdout, stderr, and troubleshooting help in error
-		result.Error = a.buildErrorWithHelp(result.Error, stderrOutput.String(), namespace, podName)
+		result.Error = a.buildErrorWithHelp(result.Error, stderrStr, stdoutStr, namespace, podName)
 	} else if parseErr != nil {
 		result.ExitCode = 1
-		result.Error = a.buildErrorWithHelp(parseErr, stderrOutput.String(), namespace, podName)
+		result.Error = a.buildErrorWithHelp(parseErr, stderrStr, stdoutStr, namespace, podName)
 	} else if resultMsg != nil && !resultMsg.IsSuccess() {
 		result.ExitCode = 1
 		if resultMsg.Error != "" {
-			result.Error = a.buildErrorWithHelp(fmt.Errorf("%s", resultMsg.Error), stderrOutput.String(), namespace, podName)
+			result.Error = a.buildErrorWithHelp(fmt.Errorf("%s", resultMsg.Error), stderrStr, stdoutStr, namespace, podName)
 		} else {
-			result.Error = a.buildErrorWithHelp(nil, stderrOutput.String(), namespace, podName)
+			result.Error = a.buildErrorWithHelp(nil, stderrStr, stdoutStr, namespace, podName)
 		}
 	}
 
@@ -320,8 +322,8 @@ func (a *Adapter) streamStderrCapture(r io.Reader, handler domain.AgentEventHand
 	}
 }
 
-// buildErrorWithHelp creates an error message with stderr output and troubleshooting help.
+// buildErrorWithHelp creates an error message with captured output and troubleshooting help.
-func (a *Adapter) buildErrorWithHelp(err error, stderr, namespace, podName string) error {
+func (a *Adapter) buildErrorWithHelp(err error, stderr, stdout, namespace, podName string) error {
 	var msg strings.Builder
 
 	if err != nil {
@@ -330,6 +332,12 @@ func (a *Adapter) buildErrorWithHelp(err error, stderr, namespace, podName strin
 		msg.WriteString("claude command failed")
 	}
 
+	// Include stdout if it contains useful output (e.g. auth errors that Claude writes to stdout)
+	if stdout != "" {
+		msg.WriteString("\n\noutput:\n")
+		msg.WriteString(stdout)
+	}
+
 	// Include stderr if available
 	if stderr != "" {
 		msg.WriteString("\n\nstderr:\n")

internal/worker/build_executor.go

@@ -221,9 +221,15 @@ func (b *BuildExecutor) Execute(ctx context.Context, task *domain.WorkTask) *dom
 		}
 	}
 
+	// Use streamed output, but fall back to agent's captured output if streaming missed it
+	output := outputBuilder.String()
+	if output == "" && agentResult.FinalOutput != "" {
+		output = agentResult.FinalOutput
+	}
+
 	result := &domain.BuildResult{
 		Success:    agentResult.Success(),
-		Output:     outputBuilder.String(),
+		Output:     output,
 		DurationMs: time.Since(start).Milliseconds(),
 		Artifacts:  make(map[string]string),
 	}