[refactor] Reorganize CLAUDE.md into hierarchical subdirectory files (#4640)

browser_tests/CLAUDE.md

@@ -0,0 +1,17 @@
+# E2E Testing Guidelines
+
+## Browser Tests
+- Test user workflows
+- Use Playwright fixtures
+- Follow naming conventions
+
+## Best Practices
+- Check assets/ for test data
+- Prefer specific selectors
+- Test across viewports
+
+## Testing Process
+After code changes:
+1. Create browser tests as appropriate
+2. Run tests until passing
+3. Then run typecheck, lint, format