fix(opencode): output error message before help in .fail() handler

[Btocode]

Issue for this PR

Closes #29390

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

When passing an invalid argument like --unknown-flag, the .fail() handler in yargs was calling cli.showHelp(show) but never output the error message msg to stderr. This meant the user saw the same output as --help with no indication of what they did wrong.

The fix writes the error message to stderr before showing the help text, so the user sees e.g. "Unknown argument: --unknown-flag" followed by the help output.

How did you verify your code works?

• Inspected the code to confirm msg contains the error string and EOL is already imported
• The change is a single line that follows the same pattern used elsewhere in the file (process.stderr.write(...))

Screenshots / recordings

N/A — CLI change only.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate PRs Found

I found two related PRs that appear to address the same issue:

1. fix(opencode): show CLI failure message before help #31228 - fix(opencode): show CLI failure message before help

   • fix(opencode): show CLI failure message before help #31228
   • Directly addresses showing error message before help text

2. fix(opencode): show error message in CLI .fail() handler #29393 - fix(opencode): show error message in CLI .fail() handler

   • fix(opencode): show error message in CLI .fail() handler #29393
   • Also targets the .fail() handler to show error messages

Both PRs appear to be fixing the same issue: ensuring error messages are displayed to the user before or instead of the help text when invalid arguments are passed. PR #31228 seems to be the most recent attempt at this fix with very similar wording to the current PR #31488.

[github-actions]

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