Verified the TDD workflow by:
1. Adding an expectation for a 'Welcome to Gemini CLI!' message to the TTY bootstrap test.
2. Observing the test failure.
3. Implementing the message in AppHeader.tsx.
4. Verifying the test pass with the built binary.
This change introduces a multi-layered validation strategy for the Gemini CLI UI, including:
- TTY Bootstrap Smoke Tests using node-pty to validate real terminal startup.
- Visual Regression Testing using SVG snapshots and AppRig.
- Core fixes for a scheduler hang and suppressed policy violations.
- Comprehensive documentation for maintainers.