Mute HyperX QuadCast S at logon and sync Windows mute to it

Sets the mic's own hardware mute (USB Audio SET_CUR mute on feature
unit 6, via IDeviceTopology/IAudioMute) when it appears, and follows its
05 10 xx HID mute reports to keep the Windows endpoint mute in step.
Includes build/install/uninstall scripts and a read-only HID listener.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build.ps1

@@ -0,0 +1,9 @@
+# Builds bin\QuadCastMuteSync.exe with the C# compiler that ships with Windows (.NET Framework 4).
+$ErrorActionPreference = 'Stop'
+$csc = Join-Path $env:WINDIR 'Microsoft.NET\Framework64\v4.0.30319\csc.exe'
+if (-not (Test-Path $csc)) { throw "csc.exe not found at $csc" }
+$bin = Join-Path $PSScriptRoot 'bin'
+New-Item -ItemType Directory -Force $bin | Out-Null
+& $csc /nologo /target:winexe /optimize+ /platform:anycpu "/out:$bin\QuadCastMuteSync.exe" "$PSScriptRoot\src\QuadCastMuteSync.cs"
+if ($LASTEXITCODE -ne 0) { throw "build failed" }
+Write-Host "Built $bin\QuadCastMuteSync.exe"