Add interactive ISAC registry filters

src/lib/components/KpiFilters.svelte

@@ -0,0 +1,23 @@
+<script lang="ts">
+	import { page } from '$app/state';
+
+	type Item = { value: string; label: string; count: string | number; description: string };
+	let { items, active = '', className = '' }: { items: Item[]; active?: string; className?: string } = $props();
+
+	function href(value: string) {
+		const params = new URLSearchParams(page.url.searchParams);
+		if (value) params.set('filter', value);
+		else params.delete('filter');
+		params.delete('page');
+		const query = params.toString();
+		return `${page.url.pathname}${query ? `?${query}` : ''}`;
+	}
+</script>
+
+<nav class={`module-kpis kpi-filters ${className}`} aria-label="Registry filters">
+	{#each items as item}
+		<a href={href(item.value)} class:active={active === item.value} aria-current={active === item.value ? 'true' : undefined}>
+			<span>{item.label}</span><strong>{item.count}</strong><small>{item.description}</small>
+		</a>
+	{/each}
+</nav>