feat(client): polished toolbar, live online count via SSE

- Redesign in-game client toolbar with refined glass styling and buttons
- Live online count + emulator status streamed over SSE multicast
- Who's-online tooltip throttled to reduce repeated requests
- Fix show button so it always returns the hidden toolbar
- Use theme CSS variables instead of hardcoded colors
- Add toolbar translations across all 25 locales

src/components/live-online-counter.tsx

@@ -0,0 +1,32 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { AnimatedCounter } from "@/components/animated-counter";
+import { useEventSource } from "@/lib/use-event-source";
+
+/**
+ * Live animated online-count number. Subscribes to the SSE online-count stream
+ * so the stat updates in real-time (multicast) instead of only the initial SSR
+ * value, while keeping the entrance counter animation.
+ */
+export function LiveOnlineCounter({
+	initial,
+	suffix = "",
+}: {
+	initial: number;
+	suffix?: string;
+}) {
+	const [count, setCount] = useState(initial);
+
+	const { data: onlineStream } = useEventSource<{ count: number }>(
+		"/api/online/count/stream",
+		{ enabled: true },
+	);
+	useEffect(() => {
+		if (onlineStream && typeof onlineStream.count === "number") {
+			setCount(onlineStream.count);
+		}
+	}, [onlineStream]);
+
+	return <AnimatedCounter value={count} suffix={suffix} />;
+}