Bug: Graph not shown if at least 2 points exists with same date

[michaelpomogajko]

When multiple points have exactly the same date, the graph doesn't show at all.

<LineGraph 
 points={[
    {
       value: 1,
       date: new Date('2023-01-01')
    },
    {
       value: 2,
       date: new Date('2023-01-01')
    }
 ]}
...
/>

[michaelpomogajko]

Also for some reason this is not being rendered as well

points={[
  {
    value: 1,
    date: new Date('2023-07-16T00:00:00.000Z'),
  },
  {
    value: 2,
    date: new Date('2023-07-19T14:23:21.723Z'),
  },
  { 
    value: 3, 
    date: new Date('2023-07-19T14:23:31.384Z') 
  },
]}

[huytdps13400]

A focused fix is now open in #131.

The reproduction still fails on current main because the zero-duration X range produces NaN, so both points are filtered before path creation. The patch keeps the matching timestamps, centers their shared X coordinate, and draws both values as a finite vertical Skia path. The regression failed before the implementation and now passes; full Jest, TypeScript, lint, and package build gates pass on Node 22.20.0.