One-command screenshot helper around gd-77_screen_grabber.py: auto-detects the
radio's serial port (cu.usbmodem* on macOS, ttyACM* on Linux) and creates a
self-contained Python venv with pyserial + pillow on first run. Saves to
screenshots/ (gitignored, along with the venv). Documented in TOOLS.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
