Add lcameraBuff Stage 2 plugin with YUV attach and unit tests.

Introduce params parsing, pixel/format decisions, capture layout, shared
YuvStimProducer per camera, and channel stimulus buffers with attach flow.

Co-authored-by: Cursor <cursoragent@cursor.com>

stimBuffApis/lcameraBuff/yuvChannelStimulusBuffer.h

@@ -0,0 +1,51 @@
+#ifndef LCAMERA_BUFF_YUV_CHANNEL_STIMULUS_BUFFER_H
+#define LCAMERA_BUFF_YUV_CHANNEL_STIMULUS_BUFFER_H
+
+#include <config.h>
+#include <user/deviceAttachmentSpec.h>
+#include <user/stagingBuffer.h>
+#include <user/stimulusBuffer.h>
+#include <pixelAndColorFormatDecisions.h>
+#define CL_TARGET_OPENCL_VERSION 120
+#include <CL/cl.h>
+#include <unistd.h>
+
+namespace smo {
+namespace stim_buff {
+namespace lcamera_buff {
+
+class YuvStimProducer;
+
+StagingBuffer::IOEngineConstraints yuvChannelStagingInputConstraints(
+	size_t channelByteSize);
+
+/**
+ * Channel stimbuff placeholder for Stage 2 setup-only attach. Uses mmap-backed
+ * StagingBuffer sized for deinterleaved Y/U/V component storage.
+ */
+class YuvChannelStimulusBuffer
+:	public StimulusBuffer
+{
+public:
+	static YuvChannelKind yuvChannelKindFromQualeIfaceApi(
+		const std::string& qualeIfaceApi);
+
+	YuvChannelStimulusBuffer(
+		StimulusProducer& parent,
+		const std::shared_ptr<device::DeviceAttachmentSpec>& deviceAttachmentSpec,
+		int histbuffMs,
+		YuvChannelKind channelKind,
+		size_t channelByteSize,
+		const SmoCallbacks& callbacks,
+		cl_mem_flags flags);
+
+public:
+	YuvChannelKind channelKind;
+	size_t channelByteSize;
+};
+
+} // namespace lcamera_buff
+} // namespace stim_buff
+} // namespace smo
+
+#endif // LCAMERA_BUFF_YUV_CHANNEL_STIMULUS_BUFFER_H