Infinite context configuration.
Optional llmWrites the summaries. infiniteContext.llmInvoker takes its place when set.
Without either, compaction runs on extractive summaries: each strategy takes
the segment's user messages (or the hybrid strategy's observation notes),
and the summary chain joins and cuts its oldest summaries.
Optional observerOptional: MemoryObserver for hybrid strategy.
Optional reflectorOptional: MemoryReflector for hybrid strategy.
Optional onEncodes a compaction's traces into long-term memory. It runs after the turn
goes on, and the ids it answers become the compaction's tracesCreated in
the log.
Maximum context window size in tokens.