chore: enable posthog pageview. (#4888)

web/core/lib/posthog-view.tsx

@@ -0,0 +1,29 @@
+'use client'
+
+import { useEffect } from "react";
+import { usePathname, useSearchParams } from "next/navigation";
+// posthog
+import { usePostHog } from 'posthog-js/react';
+
+export default function PostHogPageView(): null {
+  const pathname = usePathname();
+  const searchParams = useSearchParams();
+  const posthog = usePostHog();
+  useEffect(() => {
+    // Track pageviews
+    if (pathname && posthog) {
+      let url = window.origin + pathname
+      if (searchParams.toString()) {
+        url = url + `?${searchParams.toString()}`
+      }
+      posthog.capture(
+        '$pageview',
+        {
+          '$current_url': url,
+        }
+      )
+    }
+  }, [pathname, searchParams, posthog])
+
+  return null
+}