Get aggregate query trace statistics
Spectron context id
Phase 7.6 — response_traces_cached / response_traces_total.
§15 operational signal (#174): cross-provenance contradiction rate.
Phase 7.6 — subset with reused_from IS NOT NONE (served from the entity-aware cache).
Phase 7.6 — response_trace rows in the configured window.
§15 operational signal (#174): retrieval candidate-set breadth.
§15 operational signals (#174), aggregated over the same window: distribution of attribute provenance by source.kind.
§15 operational signal (#174): supersession churn.
Phase 7.6 — window over which the response-trace counts were aggregated.