Move Playwright, Docker, and package.json into examples/django-react-site

Root directory now contains only the two core packages (django/, react/),
examples/, and top-level docs. All e2e/integration test infrastructure
lives in examples/django-react-site/.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -21,9 +21,9 @@ package-lock.json
 .vscode/
 
 # Build artifacts
-desktop/frontend/dist/
-e2e/harness/src/api/generated.*
-e2e/harness/test-results/
+examples/django-react-desktop-app/frontend/dist/
+examples/django-react-site/harness/src/api/generated.*
+examples/django-react-site/harness/test-results/
 
 # Env
 .env