The brightness HUD broke on Tahoe because Apple deprecated/changed the
DisplayServices private framework and stopped posting the BezelEngine
distributed notifications that Atoll relied on for change detection.
This commit:
- Adds CoreBrightnessDisplayClient using Apple's CoreBrightness framework
(mirrors the existing KeyboardBrightnessClient pattern) as the primary
brightness read/write path
- Falls back gracefully to DisplayServices then IODisplay if CoreBrightness
is unavailable
- Adds a lightweight polling fallback (150ms) so the HUD fires even when
no distributed notifications are posted (Control Center, Touch Bar, auto-
brightness changes)
- Registers the new com.apple.CoreBrightness.DisplayBrightnessChanged
notification
- Fixes deprecated kIOMasterPortDefault → kIOMainPortDefault in
SystemDisplayManager.swift
Fixes#452
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>