stats: Time Range and Y-Axis Distinction

[lihz1990]

Description: There are two areas in the current statistics chart that could be optimized for a better user experience:

• Time Series Range

  • Current behavior: The time series spans from the 1st to the last day of current month.
  • Suggested improvement: Display the time range from one month ago up to today, making the data more relevant and up-to-date.

• Y-Axis Distinction

  • Current behavior: The chart has left and right y-axes, but there is no color difference between the two, making it unclear which line corresponds to which y-axis.
  • Suggested improvement: Assign different colors to the labels of the left and right y-axes, matching the color of their respective lines for better visual distinction.

These changes will help make the statistics chart more intuitive and easier to understand.

I will submit a commit with these improvements. Please review and consider merging it.

[vanadium23]

Closed by #37