[FIX] Idle income stops when navigating away from the Index page

[MrJacob12]

The game loop logic (seed generation via setInterval) is currently implemented inside
the Index.tsx page component. This causes the income generation to cease whenever the
user navigates to other routes like /packs or /collection. In an idle game, progress
should be global and persistent regardless of the active view.

Tasks:

• Move the setInterval logic from src/pages/Index.tsx to a global location (e.g.,
  App.tsx or a custom useGameLoop hook).
• Ensure the game loop starts on application mount and persists across all routes.
• Verify that updateSeeds is called correctly from the global context.