Clean up Python cache files and add .gitignore

- Remove all __pycache__ directories from tracking
- Add comprehensive .gitignore for Python projects
- Prevent future cache file commits

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

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

.gitignore

@@ -0,0 +1,28 @@
+# Python cache
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+
+# Virtual environments
+.venv/
+venv/
+env/
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Environment variables
+.env
+
+# Logs
+*.log
+
+# Test files
+test_*.json
+*_test.json