Add AI Trace plugin for AI-assisted debugging

[DenysKuchma]

Summary

Adds new aiTrace plugin that generates AI-friendly trace files for debugging failing tests with AI agents.

What it does

• Generates structured markdown trace files for each test
• Captures screenshots, HTML, ARIA snapshots, console logs
• Links to HAR files and Playwright traces
• Optimized for AI analysis

Configuration

plugins: {
  aiTrace: {
    enabled: true,
    deleteSuccessful: true,  // only keep failing tests
    ignoreSteps: [/^grab/, /^wait/]
  }

Output

For each test creates trace_/ directory with:

• trace.md - AI-friendly execution log
• 0000_screenshot.png - page screenshot
• 0000_page.html - full HTML
• 0000_aria.txt - accessibility tree
• 0000_console.json - browser console logs

Use Cases

• AI Agents: Provide context to Claude Code/GitHub Copilot for debugging
• CI/CD: Attach traces as build artifacts for failed tests
• Bug Reports: Share comprehensive reproduction artifacts
• Local Debugging: Quick investigation without re-running tests

Closes #5425

[DavertMik]

Also please ensure it works with run-workers

Pls refer to heal or analyze plugins as they should work there