[WIP] Update logs command to show errors and warnings in verbose mode

[Copilot]

Plan: Only show "Errors and Warnings" in verbose mode for logs command

• Modify buildLogsData function to accept a verbose parameter
• Update buildLogsData to conditionally populate ErrorsAndWarnings field based on verbose flag
• Pass verbose flag from DownloadWorkflowLogs to buildLogsData
• Add/update tests to verify the behavior
• Fix aggregateLogErrors to return empty slice instead of nil
• Manually test the logs command with and without verbose flag
• Run lint, build, and test to ensure no regressions

Original prompt

In "logs" command, only show "## Errors and Warnings" in verbose mode.

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