Clean up test files and incorrect brand brief

Removed:
- App-simple.tsx (debugging artifact)
- test-page.tsx (debugging artifact)
- DERAIL-ME-BRAND-BRIEF.md (incorrect brand direction)

Retained correct white-label config with proper derail.me colors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: chitcommit