Add comprehensive Python patterns to .gitignore

Added standard Python development patterns:
- Byte-compiled files (__pycache__/, *.pyc, etc.)
- Distribution/packaging artifacts
- Virtual environments (.venv, venv/, etc.)
- Testing artifacts (.pytest_cache, .coverage, etc.)
- Type checking caches (.mypy_cache/, .pytype/, etc.)
- Linting caches (.ruff_cache/)
- Jupyter notebooks and checkpoints
- IDE files (.vscode/, .idea/, *.swp)
- OS files (.DS_Store, Thumbs.db)
- UV lock file (uv.lock)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.gitignore

@@ -1 +1,72 @@
+# Project-specific
 tools/UD_repos
+tools/.go
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+*.egg
+MANIFEST
+
+# Virtual environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Testing
+.pytest_cache/
+.coverage
+.coverage.*
+htmlcov/
+.tox/
+.nox/
+
+# Type checking
+.mypy_cache/
+.dmypy.json
+dmypy.json
+.pyre/
+.pytype/
+
+# Linting
+.ruff_cache/
+
+# Jupyter
+.ipynb_checkpoints
+*.ipynb
+
+# IDEs
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# UV
+uv.lock