fix: Safari compatibility — polyfill requestIdleCallback and IntersectionObserver

requestIdleCallback is unavailable in Safari < 16.4, causing GatedProviders
to crash during hydration and blank the entire page. Added setTimeout fallback.
Also added IntersectionObserver fallback in ScrollFadeIn for safety.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/components/ScrollFadeIn.tsx

@@ -24,6 +24,12 @@ export default function ScrollFadeIn({ children, className = "", delay = 0 }: Sc
     const el = ref.current;
     if (!el) return;
 
+    // Fallback for browsers without IntersectionObserver
+    if (typeof IntersectionObserver === "undefined") {
+      setIsVisible(true);
+      return;
+    }
+
     const observer = new IntersectionObserver(
       ([entry]) => {
         if (entry.isIntersecting) {