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.cpp

@@ -0,0 +1,70 @@
+#include <yuvChannelStimulusBuffer.h>
+#include <stdexcept>
+
+namespace smo {
+namespace stim_buff {
+namespace lcamera_buff {
+
+namespace {
+
+constexpr const char *qualeIfaceColourYuvY = "colour-yuv-y";
+constexpr const char *qualeIfaceColourYuvU = "colour-yuv-u";
+constexpr const char *qualeIfaceColourYuvV = "colour-yuv-v";
+
+} // namespace
+
+YuvChannelKind YuvChannelStimulusBuffer::yuvChannelKindFromQualeIfaceApi(
+	const std::string& qualeIfaceApi)
+{
+	if (qualeIfaceApi == qualeIfaceColourYuvY) {
+		return YuvChannelKind::Y;
+	}
+
+	if (qualeIfaceApi == qualeIfaceColourYuvU) {
+		return YuvChannelKind::U;
+	}
+
+	if (qualeIfaceApi == qualeIfaceColourYuvV) {
+		return YuvChannelKind::V;
+	}
+
+	throw std::runtime_error(
+		"lcameraBuff: unsupported qualeIfaceApi '" + qualeIfaceApi
+		+ "'; expected colour-yuv-y, colour-yuv-u, or colour-yuv-v");
+}
+
+StagingBuffer::IOEngineConstraints yuvChannelStagingInputConstraints(
+	size_t channelByteSize)
+{
+	const size_t pageSize = static_cast<size_t>(sysconf(_SC_PAGE_SIZE));
+
+	return StagingBuffer::IOEngineConstraints(
+		1,
+		channelByteSize,
+		pageSize,
+		pageSize);
+}
+
+YuvChannelStimulusBuffer::YuvChannelStimulusBuffer(
+	StimulusProducer& parent,
+	const std::shared_ptr<device::DeviceAttachmentSpec>& deviceAttachmentSpec,
+	int histbuffMs,
+	YuvChannelKind _channelKind,
+	size_t _channelByteSize,
+	const SmoCallbacks& callbacks,
+	cl_mem_flags flags)
+:	StimulusBuffer(
+		parent,
+		deviceAttachmentSpec,
+		histbuffMs,
+		yuvChannelStagingInputConstraints(_channelByteSize),
+		yuvChannelStagingInputConstraints(_channelByteSize),
+		callbacks,
+		flags),
+channelKind(_channelKind),
+channelByteSize(_channelByteSize)
+{}
+
+} // namespace lcamera_buff
+} // namespace stim_buff
+} // namespace smo