fix(docs): fall back to eager video loading without IntersectionObserver

The lazy-load gate from the previous commit threw before isInView could
ever become true in environments lacking IntersectionObserver (older
browsers, some embedded webviews), leaving videos permanently
source-less instead of falling back to eager loading.

Author: waleedlatif1

apps/docs/components/ui/video.tsx

@@ -39,6 +39,14 @@ export function Video({
     // `autoPlay` forces browsers to fetch the full file immediately on mount
     // regardless of `preload` - gate the actual load behind the viewport so a
     // page with several of these doesn't pull down every video up front.
+    // Fall back to eager loading where IntersectionObserver isn't available
+    // (older browsers, some embedded webviews) rather than leave the video
+    // permanently source-less.
+    if (typeof IntersectionObserver === 'undefined') {
+      setIsInView(true)
+      return
+    }
+
     const observer = new IntersectionObserver(
       ([entry]) => {
         if (entry.isIntersecting) {