pipecat/changelog/3863.added.2.md

• Added LLMContextSummaryConfig (summary generation params: target_context_tokens, min_messages_after_summary, summarization_prompt) and LLMAutoContextSummarizationConfig (auto-trigger thresholds: max_context_tokens, max_unsummarized_messages, plus a nested summary_config). These replace the monolithic LLMContextSummarizationConfig.