Video: drive virtualTime emission off rAF for smooth minimap

src/lib/components/grid-tile.svelte

@@ -109,11 +109,32 @@
 		videoEl.playbackRate = playbackRate;
 	});
 
-	function onTimeUpdate() {
-		if (videoEl && isLeader) {
-			onLeaderTime?.(videoEl.currentTime);
-		}
-	}
+	// Drive leader-time emission off rAF instead of the <video>'s `timeupdate`
+	// event. `timeupdate` fires at ~4 Hz best-case and drops to ~1 Hz under
+	// load, which is what was making the minimap stutter. rAF is bound to the
+	// display refresh, free when paused (t doesn't change → no emit), and
+	// auto-throttled when the tab is backgrounded.
+	$effect(() => {
+		if (!isLeader || !videoEl) return;
+		const el = videoEl;
+		let cancelled = false;
+		let raf = 0;
+		let last = -1;
+		const tick = () => {
+			if (cancelled) return;
+			const t = el.currentTime;
+			if (t !== last) {
+				last = t;
+				onLeaderTime?.(t);
+			}
+			raf = requestAnimationFrame(tick);
+		};
+		raf = requestAnimationFrame(tick);
+		return () => {
+			cancelled = true;
+			cancelAnimationFrame(raf);
+		};
+	});
 
 	function onEnded() {
 		if (isLeader) onLeaderEnded?.();
@@ -181,7 +202,6 @@
 		disableremoteplayback
 		controlslist="nodownload nofullscreen noplaybackrate noremoteplayback"
 		oncontextmenu={(e) => e.preventDefault()}
-		ontimeupdate={onTimeUpdate}
 		onended={onEnded}
 		onprogress={onProgress}
 		onloadeddata={onLoadedData}

src/lib/components/video-player/video-player.svelte

@@ -83,19 +83,32 @@
 		onChunkChange?.(activeChunkIdx);
 	});
 
-	let lastEmitted = -1;
+	// Emit time on every rAF tick rather than on `<video>`'s `timeupdate` event
+	// (which fires at ~4 Hz best-case, ~1 Hz under load — visible minimap
+	// stutter). `isVideoData` gates the transient currentTime=0 that a fresh
+	// chunk's <video> reports before its loadedmetadata seek lands.
 	$effect(() => {
-		const t = currentTime;
-		// During a chunk swap the new <video> element transiently reports
-		// currentTime=0 before its loadedmetadata seek; echoing that to the
-		// parent would snap virtualTime (and therefore the minimap + timeline)
-		// back to round-start for ~1 frame. Hold off until the new clip's
-		// data has actually loaded.
-		if (!isVideoData) return;
-		if (Math.abs(t - lastEmitted) >= 0.2) {
-			lastEmitted = t;
-			onTimeUpdate?.(t);
-		}
+		if (!videoEl) return;
+		const el = videoEl;
+		let cancelled = false;
+		let raf = 0;
+		let last = -1;
+		const tick = () => {
+			if (cancelled) return;
+			if (isVideoData) {
+				const t = el.currentTime;
+				if (t !== last) {
+					last = t;
+					onTimeUpdate?.(t);
+				}
+			}
+			raf = requestAnimationFrame(tick);
+		};
+		raf = requestAnimationFrame(tick);
+		return () => {
+			cancelled = true;
+			cancelAnimationFrame(raf);
+		};
 	});
 
 	function chunksSig(cs: Chunk[]): string {