web: name the MediaSession track "The Falls"

The web shell sets its own now-playing metadata (not from the snapshot), so update
the MediaSession artist from "Waterfall loop" to "The Falls" to match the core.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: JacobStephens2

apps/web/src/core/useCascade.ts

@@ -221,7 +221,7 @@ export function useCascade(): UseCascadeResult {
     const ms = navigator.mediaSession;
     ms.metadata = new MediaMetadata({
       title: "Cascade",
-      artist: "Waterfall loop",
+      artist: "The Falls",
       artwork: [
         { src: "/icon-192.png", sizes: "192x192", type: "image/png" },
         { src: "/icon-512.png", sizes: "512x512", type: "image/png" },