The capture-direction lookup built its endpoint id with the RENDER prefix
{0.0.0.00000000}., but WASAPI's enumeration returns capture ids as
{0.0.1.00000000}.{guid} — so the minted microphone's capture side never
string-matched the enumeration and the wiring plan paired no recording
device (audio-probe plan on the target box: mic_capture = '-'). Measured;
IMMDeviceEnumerator::GetDevice tolerated the wrong prefix, which is why
the S3 spike's direct open still passed.