feat: add activity level legend to spot view

apps/web/src/pages/spots/[id].astro

@@ -35,6 +35,7 @@ const breadcrumbs = spot ? { "@context": "https://schema.org", "@type": "Breadcr
     <section class="spot-hero"><div><span class="eyebrow">{spot.waterbody}</span><h1>Точка {spot.x}:{spot.y}</h1><p>{spot.description}</p><button class="coordinate-copy" type="button" data-copy-coordinates={`${spot.x}:${spot.y}`}>Скопировать координаты</button><small class="copy-status" aria-live="polite"></small></div><CoordinateRadar x={spot.x} y={spot.y}/></section>
     <div class="periods"><div><strong>{spot.catches_24h}</strong><span>за 24 часа</span></div><div><strong>{spot.catches_3d}</strong><span>за 3 дня</span></div><div><strong>{spot.catches_7d}</strong><span>за 7 дней</span></div></div>
     <ActivityTimeline buckets={timeline}/>
+    <div class="activity-legend" aria-label="Уровни активности"><span>Тихо</span><span>Есть сигналы</span><span>Горячо</span></div>
     <section class="detail-grid">
       <div>
         <div class="section-heading"><h2>Последние уловы</h2></div>