@spec avg_latency() :: number()

Returns average latency across prompt-run results, or zero when unavailable.

@spec comparison_stats(pos_integer()) :: map()

Compares the current period with the immediately preceding period.

The period defaults to seven days. Counts, quality, cost, latency, stability, regression signals, and total-run trend are calculated with bounded period queries.

@spec comparison_stats(pos_integer(), DateTime.t()) :: map()

Compares adjacent periods ending at the supplied UTC timestamp.

@spec rolling_comparisons(DateTime.t()) :: %{required(pos_integer()) => map()}

Returns seven-day and thirty-day period comparisons keyed by window length.

@spec success_rate(integer(), integer()) :: float()

Calculates a percentage success rate, returning 0.0 when no tests exist.

@spec test_totals() :: {integer(), integer()}

Returns total passed and failed tests across suite runs.

@spec total_runs() :: integer()

Counts all recorded prompt runs and suite runs.