Feature: CLI tool and Shortcuts support for display control #1886

Interested in contributing CLI and Shortcuts support for MonitorControl. This would address several prior requests (#1601, #1515, #1620).

What's built so far (on my fork):

• A lightweight monitorcontrol CLI bundled inside the app bundle
• Uses DistributedNotificationCenter to talk to the running app — no new dependencies
• Supports list, get <property>, set <property> <value> with --display targeting and --json output
• Proper exit codes, stderr for errors, UUID-scoped replies

Example usage:

monitorcontrol list
monitorcontrol get brightness --display "LG"
monitorcontrol set volume 50 --display 2

Next step would be App Intents / Shortcuts integration, reusing the same control logic.

The CLI requires the app to be running (no daemon, no extra processes). Happy to open a PR if there's interest, or adjust the approach based on feedback.