Keep the tray menu responsive during HID polling

[vermi5]

What changed

• Run controller, Dock, and automatic lighting HID refresh work off the WinForms UI thread.
• Coalesce overlapping refresh requests and serialize HID access across refresh, diagnostics, and lighting operations.
• Publish completed snapshots back through the UI timer.
• Document the background refresh architecture and user-facing fix.

Why

The synchronous refresh path could wait several seconds for controller or Dock
HID reports while running on the Windows message loop. If a right-click landed
during that work, the tray context menu could not open until the timeout
completed.

Impact

The tray menu remains responsive while a controller wakes, the Dock is quiet,
or HID reads time out. The last published battery state remains visible until
the background refresh completes.

Validation

• Compiled all application sources with the .NET Framework C# compiler using /warn:4.
• Ran VaderLedProtocolSelfTest.exe successfully.
• Ran git diff --check successfully.