Persist last-picked date range on Statistics page

[chelzakaria]

Description: Remember the user’s last selected date range, so the Statistics page doesn’t reset to the default when revisiting.

Tasks:

• Store the selected date range locally (e.g., localStorage).
• Load that stored range on page load; fall back to the current default if missing/invalid.
• Ensure fetches and charts use the restored range.

Acceptance Criteria:

• Revisiting the page restores the previous range.
• No duplicate fetches; charts and filters work as before.

[Swapnil-Ghodse]

Hello @chelzakaria ,

I would like to work on this issue.