get aggregated session analytics

Returns aggregated latency analytics across sessions — percentile distributions (p50/p90/p95/p99/max/avg) for each stage of the transcription → LLM → TTS → first-audio path, interruption and error rates, tool call outcomes, and a sample of the slowest turns. Only sessions where Anam runs the conversational pipeline (turnkey, custom LLM and ElevenLabs agent sessions) produce analytics reports; LiveKit and audio-passthrough sessions count toward sessionCount but never carry analytics. Defaults to the last 24 hours; the maximum range is 31 days. Reports are aggregated from the 1000 most recent report-capable sessions matching the filters — session types that never produce reports don't consume that window — and the truncated field reports when more report-capable sessions matched. Narrow the time range or filters to analyse busier periods exhaustively.