perf: optimize data path, indexes and frontend virtualization

- Убран latestCDNRowsBySource; expanded BIRD preview генерируется on-demand
- Batch AS meta updates; миграция perf-индексов 000012
- VirtualPrefixList для preview префиксов; метрики pipeline refresh
- PolitePause для RIPEstat после cache miss

Co-authored-by: Cursor <[email protected]>

web/src/lib/ui/patterns/virtual-list/virtual-prefix-list.svelte

@@ -0,0 +1,37 @@
+<script lang="ts">
+	type Props = {
+		items: readonly string[];
+		rowHeight?: number;
+		viewportHeight?: number;
+		class?: string;
+	};
+
+	let { items, rowHeight = 20, viewportHeight = 320, class: className = '' }: Props = $props();
+
+	let scrollTop = $state(0);
+	const totalHeight = $derived(items.length * rowHeight);
+	const startIndex = $derived(Math.max(0, Math.floor(scrollTop / rowHeight) - 2));
+	const visibleCount = $derived(Math.ceil(viewportHeight / rowHeight) + 4);
+	const visibleItems = $derived(items.slice(startIndex, startIndex + visibleCount));
+</script>
+
+<div
+	class="overflow-auto rounded-md border {className}"
+	style="height: {viewportHeight}px"
+	onscroll={(e) => {
+		scrollTop = e.currentTarget.scrollTop;
+	}}
+>
+	<div style="height: {totalHeight}px; position: relative">
+		{#each visibleItems as pfx, i (`${startIndex + i}-${pfx}`)}
+			<p
+				class="font-mono text-xs leading-5 truncate px-2"
+				style="position: absolute; top: {(startIndex + i) * rowHeight}px; left: 0; right: 0; height: {rowHeight}px"
+			>
+				{pfx}
+			</p>
+		{:else}
+			<p class="text-muted-foreground p-2 text-sm">Нет префиксов</p>
+		{/each}
+	</div>
+</div>