fix(errors): drop third-party plyr xhr noise from global error screen

Sentry wraps XMLHttpRequest and injects an app-origin stack frame, so the
hostname-based external-noise filter fails to drop errors thrown from
cdn.plyr.io. Treat plyr-originated errors as external noise so a network
hiccup in the player never triggers the full-page error screen.

Author: seferturan

projects/client/src/lib/features/errors/ErrorProvider.svelte

@@ -61,7 +61,13 @@
       // browser extensions as a second copy alongside Plyr's own instance.
       // When the iframe is torn down during SPA navigation the orphaned
       // API copy accesses stale registry entries; not actionable for us.
-      error.stack?.includes("www-widgetapi.js");
+      error.stack?.includes("www-widgetapi.js") ||
+      // Plyr's own scripts throw from an XHR error listener on network-layer
+      // failures (e.g. Error: 0). Sentry wraps XMLHttpRequest and injects an
+      // app-origin frame, so the hostname check above lets these through even
+      // though the originating frame is third-party. A cosmetic player hiccup
+      // must not escalate to the full-page error screen.
+      error.stack?.includes("cdn.plyr.io");
 
     if (isExternalNoise) return;