feat(frontend): Add balance visibility toggle with blur effect

Co-authored-by: elisiariocouto <818914+elisiariocouto@users.noreply.github.com>

frontend/src/components/ui/balance-toggle.tsx

@@ -0,0 +1,26 @@
+import { Eye, EyeOff } from "lucide-react";
+import { Button } from "./button";
+import { useBalanceVisibility } from "../../contexts/BalanceVisibilityContext";
+
+export function BalanceToggle() {
+  const { isBalanceVisible, toggleBalanceVisibility } = useBalanceVisibility();
+
+  return (
+    <Button
+      variant="outline"
+      size="icon"
+      onClick={toggleBalanceVisibility}
+      className="h-8 w-8"
+      title={isBalanceVisible ? "Hide balances" : "Show balances"}
+    >
+      {isBalanceVisible ? (
+        <Eye className="h-4 w-4" />
+      ) : (
+        <EyeOff className="h-4 w-4" />
+      )}
+      <span className="sr-only">
+        {isBalanceVisible ? "Hide balances" : "Show balances"}
+      </span>
+    </Button>
+  );
+}