Make footer visible only with scroll

[mariana2103]

One way to do it:

• Create a new file called FooterWrapper.tsx inside src/components/layout/.
• Do NOT change Footer.tsx
• In the /src/components/layout/index.tsx where we currently have Footer , replace it with FooterWrapper so the wrapper controls when the footer appears.

What to do in the wrapper:

• Create a state variable that starts as false (footer hidden). (using useState)
• Add a scroll listener using useEffect that checks window.scrollY.
• Add a check that makes the footer visible once window.scrollY passes a small threshold (around 100px), so it only appears after the user starts scrolling.
• When the state is true, show the footer; when false, hide it.
• Wrap the inside a div whose CSS classes depend on that state (opacity 0 when hidden, opacity 100 when visible).