completeWithContext method
RAG: Complete with pre-retrieved context (optional - check capabilities.rag).
Consumer builds a ContextBundle via ContextBundlePort /
RetrievalPort first, then passes it here for grounded generation.
Implementation
Future<LlmResponse> completeWithContext(
LlmRequest request,
ContextBundle context,
) {
throw UnsupportedError('RAG not supported by this LLM');
}