fix(billing): remove redundant account bootstrap request

Co-Authored-By: Claude Code <noreply@anthropic.com>

frontend/src/lib/billing-panel-loader.ts

@@ -3,5 +3,7 @@ export function loadBillingPanel() {
 }
 
 export function prefetchBillingPanel(): void {
-  void loadBillingPanel();
+  // Hover/pointer prefetch is opportunistic. An offline chunk failure must not
+  // become an unhandled rejection handled by StaleClientRecovery as a reload.
+  void loadBillingPanel().catch(() => undefined);
 }