[plan] Add visual regression reference workflow using playwright + cache-memory

[github-actions]

Objective

Add a reference workflow that demonstrates visual regression testing using playwright + cache-memory for baseline screenshot storage. This addresses the lowest-scoring scenario (FE-1, 3.8/5.0) from the Agent Persona Exploration discussion #18250.

Context

The agent correctly suggests playwright for screenshots but leaves baseline comparison storage unaddressed. Without a reference workflow showing how to store "before" screenshots using cache-memory or artifacts, visual regression workflows are incomplete.

Approach

1. Create .github/workflows/visual-regression.md as a reference workflow that:
   • Triggers on pull_request
   • Uses playwright for capturing screenshots
   • Uses cache-memory to persist baseline screenshots between runs
   • Compares current screenshots against stored baselines
   • Uses safe-outputs to post a comment with the diff report
2. Follow the pattern of existing reference workflows like auto-triage-issues.md
3. Ensure filesystem-safe timestamp formats (no colons) in cache-memory filenames

Files to Create/Modify

• Create: .github/workflows/visual-regression.md (and recompile to generate .lock.yml)

Acceptance Criteria

• Reference workflow exists and compiles successfully
• Workflow demonstrates baseline storage with cache-memory
• Workflow posts visual diff report via safe-outputs
• Workflow follows security best practices (minimal permissions, safe-outputs for writes)
• The agentic-workflows agent can use this as a reference when asked about visual regression

Generated by Plan Command for issue #discussion #18250

• expires on Feb 27, 2026, 4:46 AM UTC

[pelikhan]

Create .github/aw/visual-regression.md