DEV - Auto-refetch all app data every 5 minutes and on full page reload #410

Overview

Set up a global polling interval that calls all data-fetch methods every 5 minutes. All app data should also be fetched fresh on a full page reload with no stale cache served.

Tasks

• Identify all data-fetch methods across the app (grants, users, cashflow, dashboard stats, etc.) and create a single function that calls each of them
• Call the function once on app mount to ensure fresh data on full page reload
• Set up an interval on app mount
• Clear the interval in the component cleanup / unmount to prevent memory leaks
• Verify only one interval is ever active at a time
• Manual test: leave the app open for 5+ minutes and confirm data updates without a page reload

Acceptance criteria

• A single timer calls all fetch methods every 5 minutes.
• Interval starts on app mount and is cleared on unmount (no stacked intervals).
• All data is fetched fresh on full page reload.
• Uses existing fetch methods (no new endpoints needed).