[idd] audio: add virtual playback and capture driver

Add a WaveRT adapter with render and capture endpoints backed by a
local ring buffer and shared presentation clock.

Advertise PCM formats through 192 kHz, eight channels, and packed
24-bit samples. Register LGAudio in the IDD solution and package it as
Looking Glass Audio.

idd/LGAudio/Adapter.h

@@ -0,0 +1,76 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#pragma once
+
+#include "AudioClock.h"
+#include "Common.h"
+#include "RingBuffer.h"
+
+class CAudioAdapter final : public IUnknown
+{
+public:
+  CAudioAdapter();
+  ~CAudioAdapter();
+
+  NTSTATUS Initialize();
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  NTSTATUS ConfigureRender(
+    _In_ const FormatFingerprint &format);
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  void ResetCapture();
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  void WriteRenderFrames(
+    _In_reads_bytes_(bytes) const BYTE *data,
+    _In_ ULONG bytes);
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  void ReadCaptureFrames(
+    _In_ const FormatFingerprint &format,
+    _Out_writes_bytes_(bytes) BYTE *data,
+    _In_ ULONG bytes);
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  void DiscardCaptureFrames(
+    _In_ const FormatFingerprint &format,
+    _In_ ULONGLONG bytes);
+
+  _IRQL_requires_max_(DISPATCH_LEVEL)
+  AudioClockSnapshot GetClockSnapshot() const;
+
+  STDMETHODIMP_(NTSTATUS) QueryInterface(
+    _In_ REFIID interfaceId,
+    _COM_Outptr_ void **object) override;
+  STDMETHODIMP_(ULONG) AddRef() override;
+  STDMETHODIMP_(ULONG) Release() override;
+
+private:
+  volatile LONG m_refCount;
+  CAudioClock m_clock;
+  CAudioRingBuffer m_ring;
+};
+
+NTSTATUS StartAudioDevice(
+  _In_ PDEVICE_OBJECT deviceObject,
+  _In_ PIRP irp,
+  _In_ PRESOURCELIST resourceList);