🎨 style(footer): remove redundant bg-semi-color-bg-2 class (#1354)

The background utility class `bg-semi-color-bg-2` was unnecessary after recent
design adjustments and unintentionally overrode intended styles.
Removing it cleans up the markup and allows the footer to inherit the correct
background from its parent containers.

File affected:
- web/src/components/layout/Footer.js

Closes #1354

web/src/components/layout/Footer.js

@@ -22,7 +22,7 @@ const FooterBar = () => {
   const currentYear = new Date().getFullYear();
 
   const customFooter = useMemo(() => (
-    <footer className="relative bg-semi-color-bg-2 h-auto py-16 px-6 md:px-24 w-full flex flex-col items-center justify-between overflow-hidden">
+    <footer className="relative h-auto py-16 px-6 md:px-24 w-full flex flex-col items-center justify-between overflow-hidden">
       <div className="absolute hidden md:block top-[204px] left-[-100px] w-[151px] h-[151px] rounded-full bg-[#FFD166]"></div>
       <div className="absolute md:hidden bottom-[20px] left-[-50px] w-[80px] h-[80px] rounded-full bg-[#FFD166] opacity-60"></div>