pipecat/changelog/4265.fixed.md

• Fixed ElevenLabsTTSService incorrectly enabling auto_mode when using TextAggregationMode.TOKEN. Auto mode disables server-side buffering and is designed for complete sentences — enabling it with token streaming degraded speech quality. The default is now derived automatically from the aggregation strategy: auto_mode=True for SENTENCE, auto_mode=False for TOKEN. Callers can still override by passing auto_mode explicitly.