Description

Apply output escaping to all linting scripts to prevent GitHub Actions workflow command injection vulnerabilities. When exception messages or file paths contain special characters (%, \r, \n, ::), they could be interpreted as workflow commands. This change escapes these characters before emitting ::error:: or ::warning:: annotations.

Changes:

• Add inline escaping pattern to six linting script error handlers: Invoke-LinkLanguageCheck.ps1, Invoke-PSScriptAnalyzer.ps1, Invoke-YamlLint.ps1, Link-Lang-Check.ps1, Markdown-Link-Check.ps1, Validate-MarkdownFrontmatter.ps1
• Update Write-GitHubAnnotation in LintingHelpers.psm1 to escape both message content and file path properties
• Property values receive additional :/, escaping per GitHub Actions annotation syntax requirements

Related Issue(s)

Closes #364

Type of Change

Select all that apply:

Code & Documentation:

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Infrastructure & Configuration:

• GitHub Actions workflow
• Linting configuration (markdown, PowerShell, etc.)
• Security configuration
• DevContainer configuration
• Dependency update

AI Artifacts:

• Reviewed contribution with prompt-builder agent and addressed all feedback
• Copilot instructions (.github/instructions/*.instructions.md)
• Copilot prompt (.github/prompts/*.prompt.md)
• Copilot agent (.github/agents/*.agent.md)

Note for AI Artifact Contributors:

• Agents: Research, indexing/referencing other project (using standard VS Code GitHub Copilot/MCP tools), planning, and general implementation agents likely already exist. Review .github/agents/ before creating new ones.
• Model Versions: Only contributions targeting the latest Anthropic and OpenAI models will be accepted. Older model versions (e.g., GPT-3.5, Claude 3) will be rejected.
• See Agents Not Accepted and Model Version Requirements.

Other:

• Script/automation (.ps1, .sh, .py)
• Other (please describe):

Sample Prompts (for AI Artifact Contributions)

N/A - This is a script change, not an AI artifact contribution.

Testing

• Verified escaping pattern matches GitHub's official @actions/core implementation
• Pattern tested against edge cases: %, \r, \n, :: in exception messages

Checklist

Required Checks

• Documentation is updated (if applicable)
• Files follow existing naming conventions
• Changes are backwards compatible (if applicable)
• Tests added for new functionality (if applicable)

AI Artifact Contributions

N/A

Required Automated Checks

The following validation commands must pass before merging:

• Markdown linting: npm run lint:md
• Spell checking: npm run spell-check
• Frontmatter validation: npm run lint:frontmatter
• Link validation: npm run lint:md-links
• PowerShell analysis: npm run lint:ps

Security Considerations

• This PR does not contain any sensitive or NDA information
• Any new dependencies have been reviewed for security issues
• Security-related scripts follow the principle of least privilege

Additional Notes

This is part of a series of PRs applying CI output escaping across the codebase. Related PRs address security scripts (#365) and infrastructure scripts (#366).