Self-contained Python scripts with uv

Python scripts can now use uv in the shebang line to create self-contained executables. This allows scripts to manage their own dependencies and virtual environments without user intervention. By adding a special comment with package requirements and using #!/usr/bin/env -S uv python as the shebang, scripts become portable and easily executable on any system with uv installed. This approach simplifies sharing and running Python scripts, eliminating the need for manual environment setup or system-wide package installation.