Locked 2026-08-21 (D7). Extend UsageChartsResponse with coverage data derived from segments: gaps / longest-run KPIs for the Range view, and the hour×day heatmap's hollow (captured but idle) vs blank (not captured) distinction. No coverage fields exist today.
Locked 2026-08-21 (D7). Extend
UsageChartsResponsewith coverage data derived from segments: gaps / longest-run KPIs for the Range view, and the hour×day heatmap's hollow (captured but idle) vs blank (not captured) distinction. No coverage fields exist today.