fix: detect CSS preload errors and keep banner visible during error states

- Add "unable to preload" pattern to isChunkError for Vite CSS preload failures
- Move ConnectionMonitor and ConnectionBanner outside ErrorBoundary so they
  remain visible when the error boundary catches a render crash
- Add test for CSS preload error retry

apps/web/src/lib/lazy-with-retry.ts

@@ -7,7 +7,8 @@ export function isChunkError(error: unknown): boolean {
     msg.includes("dynamically imported module") ||
     msg.includes("loading chunk") ||
     msg.includes("loading css chunk") ||
-    msg.includes("failed to fetch")
+    msg.includes("failed to fetch") ||
+    msg.includes("unable to preload")
   );
 }