Power Display: Tray icon redesign with per-monitor icons or assignable scroll target

Description of the new feature / enhancement

The current tray icon is a single generic white monitor glyph carrying no information. Two acceptable approaches, in order of preference:

• Option A (preferred): one tray icon per monitor, each showing a large legible numeral, with scroll wheel support on each icon individually (see #48320).
• Option B (fallback): keep a single tray icon, but allow the user to assign the scroll wheel target to a specific monitor in settings.

Scenario when this would be used?

With multiple monitors, the current single tray icon gives no indication of which display is being controlled. A per-monitor icon with a large numeral would make the active display immediately identifiable at a glance and enable direct per-monitor brightness control without opening the flyout. This is how Twinkle Tray handles it, and it significantly reduces interaction cost for multi-monitor setups.

Supporting information

• Related feature request: #48320
• Twinkle Tray (Microsoft Store)
• ClickMonitorDDC implements per-monitor tray icons and scroll wheel on tray icon

Start by reviewing the current PowerToys tray icon behavior and related feature request #48320, then compare the referenced Twinkle Tray and ClickMonitorDDC behavior. Done means implementing and validating either per-monitor numbered tray icons with individual scroll targets or the fallback assignable scroll target in settings, with the chosen approach clearly documented.