fix: bar chart white hover cursor on dark theme

Recharts BarChart default tooltip cursor renders a white Rectangle
on hover which washes out the dark theme. Set cursor fill to grid
color with low opacity for a subtle theme-appropriate highlight.
Fixes addons "By package" and deposits "By payment method" charts.

src/components/sales-stats/SimpleBarChart.tsx

@@ -71,6 +71,7 @@ export function SimpleBarChart({
             allowDecimals={false}
           />
           <Tooltip
+            cursor={{ fill: colors.grid, fillOpacity: 0.3 }}
             contentStyle={{
               backgroundColor: colors.tooltipBg,
               border: `1px solid ${colors.tooltipBorder}`,