HandBrake via HandBrakeCLI

HandBrake is driven through HandBrakeCLI, the command-line encoder built from the same libhb as the GUI. The GUI has no scripting interface, and HandBrake.app does not contain the CLI. Install it separately (brew install handbrake, or HandBrakeCLI-<version>.dmg from handbrake.fr/downloads2.php). Verified against HandBrake 1.11.2 (Homebrew build, arm64) on macOS 27.

The scripts wrap the CLI's sharp edges: they scan before encoding, resolve tracks, force square pixels, write outputs atomically, and parse the JSON progress.