StimulusProducer: add duplicate-quale guard and attach-identity buffer lookup.

Provide ensureNoDuplicateQualeIface and getAttachedStimulusBufferByAttachIdentity
so session-scoped stimBuff plugins can reject duplicate quales and detach by
stable DAP line identity rather than full spec equality.

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

commonLibs/attachmentSupport/stimulusProducer.cpp

@@ -82,6 +82,32 @@ std::shared_ptr<StimulusBuffer> StimulusProducer::getAttachedStimulusBuffer(
 	return nullptr;
 }
 
+std::shared_ptr<StimulusBuffer> StimulusProducer::getAttachedStimulusBufferByAttachIdentity(
+	const std::string& deviceIdentifier,
+	const std::string& qualeIfaceApi) const
+{
+	for (const auto& buffer : attachedStimulusBuffers)
+	{
+		if (!buffer || !buffer->deviceAttachmentSpec)
+		{
+			throw std::runtime_error(
+				"StimulusProducer::getAttachedStimulusBufferByAttachIdentity: "
+				"encountered null buffer or null deviceAttachmentSpec in "
+				"attachedStimulusBuffers (should never happen)");
+		}
+
+		if (buffer->deviceAttachmentSpec->deviceIdentifier != deviceIdentifier)
+			{ continue; }
+
+		if (buffer->deviceAttachmentSpec->qualeIfaceApi != qualeIfaceApi)
+			{ continue; }
+
+		return buffer;
+	}
+
+	return nullptr;
+}
+
 bool StimulusProducer::hasBufferWithQualeIfaceApi(
 	const std::string& qualeIfaceApi) const
 {
@@ -104,6 +130,18 @@ bool StimulusProducer::hasBufferWithQualeIfaceApi(
 	return false;
 }
 
+void StimulusProducer::ensureNoDuplicateQualeIface(
+	const std::string& qualeIfaceApi) const
+{
+	if (!hasBufferWithQualeIfaceApi(qualeIfaceApi)) {
+		return;
+	}
+
+	throw std::runtime_error(
+		"duplicate qualeIface '" + qualeIfaceApi
+		+ "' for this producer session");
+}
+
 bool StimulusProducer::addAttachedStimulusBufferIfNotExists(
 	const std::shared_ptr<StimulusBuffer>& buffer)
 {