Multi line text update in work item discussion

[nuthanm]

Is your feature request related to a problem? Please describe.
Yes. Currently, the az boards work-item update --discussion command does not support multi-line comments. When attempting to pass a string with line breaks (either via here-strings, escaped \n, or file input using @file.txt), only the first line is recorded in the work item discussion. This limitation significantly reduces the usefulness of the command for real-world collaboration, where formatted updates or daily activity summaries often require multiple lines for clarity.

Describe the solution you'd like
I would like az boards work-item update --discussion to support full multi-line text input, respecting newline characters and preserving formatting when:

Passing multi-line strings via PowerShell or Bash (with \n)

Using here-strings in PowerShell (@"..."@)

Using @file.txt syntax to load the comment from a file

This enhancement would allow users to provide richer, more structured updates directly from the CLI, aligning with the way discussions are typically written in the Azure DevOps portal UI.

Additional context
This limitation impacts:

• Automation scripts for daily standups or deployment notes
• DevOps teams using CLI for faster workflow integration
• Users preferring structured bullet points or markdown-style formatting

Workarounds like flattening updates into a single line using | or switching to the REST API are not ideal. Full support for multi-line input in --discussion would improve the CLI’s usability and consistency with the Azure DevOps web interface.