[BUG] Use total-time data for the registry history chart’s seconds axis

[lukekarrys]

Problem

app/src/hooks/use-history-data.ts currently prefers registryPerPackageCountChartData over registryChartData when extracting registry history. Those values are normalized milliseconds per package, while history-chart.tsx treats registry history values as total seconds.

The result is a unit mismatch: values such as 60.14/90.18 are plotted and labeled as seconds even though they came from the per-package series. The hook’s own comment says registry variations should use total-time data.

Proposed fix

Prefer registryChartData for registry history and use per-package data only in a UI that is explicitly labeled in ms/package. Preserve a sensible fallback for older data files.

Acceptance criteria

• Registry history uses total-time registryChartData when available.
• The y-axis and tooltip units match the selected source.
• Older chart-data files without the preferred source still render safely.
• Tests cover both current and legacy payload shapes.

Source

Performance investigation: item 2 — registry history unit mismatch