perf(studio): speed up nitro scan and stop the cleanup panel freezing

src/components/admin/studio/nitro-cleanup-panel.tsx

@@ -63,6 +63,13 @@ type AssetKind = "nitro" | "swf" | "icon";
 
 const DAY_MS = 24 * 60 * 60 * 1000;
 
+/**
+ * How many rows a group renders at once. Directories can contain tens of
+ * thousands of leftover files; mounting every row as DOM nodes freezes the
+ * tab, so rows are added in chunks via a "load more" button.
+ */
+const RENDER_CHUNK = 500;
+
 function ageLabel(lastModified: number): string {
 	if (!lastModified) return "age unknown";
 	const days = Math.floor((Date.now() - lastModified) / DAY_MS);
@@ -103,8 +110,11 @@ function CleanupGroup({
 	onToggle: (fileName: string) => void;
 	onToggleAll: (names: string[]) => void;
 }) {
+	const [shown, setShown] = useState(RENDER_CHUNK);
+
 	const checked = entries.filter((e) => selected.has(e.fileName));
 	const allChecked = entries.length > 0 && checked.length === entries.length;
+	const visibleEntries = entries.slice(0, shown);
 	const toneClass =
 		tone === "error"
 			? "border-[var(--admin-error-border)] bg-[var(--admin-error-subtle)]"
@@ -148,8 +158,9 @@ function CleanupGroup({
 					No {label.toLowerCase()} found
 				</p>
 			) : (
+				<>
 					<ul className="max-h-80 space-y-1 overflow-auto rounded-lg border border-[var(--admin-border)] bg-[var(--admin-surface)] p-2">
-					{entries.map((entry) => (
+						{visibleEntries.map((entry) => (
 							<li
 								key={entry.fileName}
 								className="flex items-center gap-2 rounded-md px-2 py-1.5 text-sm hover:bg-[var(--admin-accent)]/5"
@@ -187,6 +198,23 @@ function CleanupGroup({
 							</li>
 						))}
 					</ul>
+					{entries.length > shown && (
+						<div className="flex items-center justify-between px-2 text-xs text-[var(--admin-text-muted)]">
+							<span>
+								Showing {shown} of {entries.length}
+							</span>
+							<Button
+								type="button"
+								variant="outline"
+								size="sm"
+								disabled={disabled}
+								onClick={() => setShown((s) => s + RENDER_CHUNK)}
+							>
+								Load {Math.min(RENDER_CHUNK, entries.length - shown)} more
+							</Button>
+						</div>
+					)}
+				</>
 			)}
 		</section>
 	);

src/lib/services/nitro-cleanup.ts

@@ -217,14 +217,21 @@ interface DirectoryRead {
 	lastModified: number;
 }
 
+/**
+ * How many `stat` calls run in parallel while reading an asset directory.
+ * Directories can hold hundreds of thousands of files; serial `stat`ing them
+ * is the single biggest cost of the scan, so the work is spread over a pool.
+ */
+const DIR_STAT_CONCURRENCY = 32;
+
 async function readAssetDir(
 	dir: string,
 	regex: RegExp,
 ): Promise<DirectoryRead[]> {
 	const names = await fs.readdir(dir).catch(() => [] as string[]);
 	const entries: DirectoryRead[] = [];
-	for (const name of names) {
-		if (!regex.test(name)) continue;
+	await runPool(names, DIR_STAT_CONCURRENCY, async (name) => {
+		if (!regex.test(name)) return;
 		let size = 0;
 		let mtimeMs = 0;
 		try {
@@ -240,7 +247,7 @@ async function readAssetDir(
 			size,
 			lastModified: mtimeMs,
 		});
-	}
+	});
 	return entries;
 }
 
@@ -321,7 +328,7 @@ export async function scanFakeBrokenNitros(): Promise<NitroCleanupScan> {
 	const fake: NitroCleanupEntry[] = [];
 	const broken: NitroCleanupEntry[] = [];
 
-	await runPool(entries, 8, async (entry) => {
+	await runPool(entries, 16, async (entry) => {
 		// A .nitro that no DB item maps to is a leftover / fake bundle.
 		if (!validStems.has(entry.base.toLowerCase())) {
 			fake.push(entry);