chore: import upstream snapshot with attribution

examples/integrations/a2a-middleware/.gitignore

@@ -0,0 +1,84 @@
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+*.pyc
+venv/
+env/
+ENV/
+env.bak/
+venv.bak/
+
+# Virtual environments
+agents/.venv/
+agents/venv/
+.venv/
+
+# Node
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.pnpm-debug.log*
+lerna-debug.log*
+.next/
+out/
+.turbo
+.vercel
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# Testing
+coverage/
+.coverage
+.pytest_cache/
+.nyc_output/
+htmlcov/
+
+# Logs
+logs/
+*.log
+
+# Temporary files
+*.tmp
+*.temp
+.cache/
+.parcel-cache/
+
+# OS
+Thumbs.db
+Desktop.ini
+
+# Build outputs
+*.tsbuildinfo
+next-env.d.ts