chore: add .gitignore for Python and session files

.gitignore

@@ -0,0 +1,33 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+*.egg-info/
+dist/
+build/
+
+# Environment
+.env
+.env.*
+.venv/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Session notes (local only)
+session.md
+*.session.md
+
+# Logs
+*.log
+logs/