perf(landing): share one SSE socket for online counters, respect reduced motion

Header and hero/stats counters each opened their own EventSource to the
online-count stream; a shared subscriber now opens a single socket and
multicasts to every mounted counter. The entrance count-up animation skips
its requestAnimationFrame loop when the user prefers reduced motion.

src/components/animated-counter.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { motion, useInView } from "motion/react";
+import { motion, useInView, useReducedMotion } from "motion/react";
 import { useEffect, useRef, useState } from "react";
 
 export function AnimatedCounter({
@@ -12,6 +12,7 @@ export function AnimatedCounter({
 }) {
 	const ref = useRef<HTMLSpanElement>(null);
 	const isInView = useInView(ref, { once: true, margin: "-50px" });
+	const prefersReducedMotion = useReducedMotion();
 	const started = useRef(false);
 	const [display, setDisplay] = useState(0);
 
@@ -24,6 +25,11 @@ export function AnimatedCounter({
 		}
 		started.current = true;
 
+		if (prefersReducedMotion) {
+			setDisplay(value);
+			return;
+		}
+
 		const duration = 1200;
 		const start = performance.now();
 		let raf = 0;
@@ -41,7 +47,7 @@ export function AnimatedCounter({
 
 		raf = requestAnimationFrame(tick);
 		return () => cancelAnimationFrame(raf);
-	}, [isInView, value]);
+	}, [isInView, value, prefersReducedMotion]);
 
 	return (
 		<motion.span