maps update corp

src/routes/weather/maps/+page.svelte

@@ -1,11 +1,32 @@
 <script lang="ts">
+	import { onMount } from 'svelte';
+
 	import { storedLocation } from '$lib/stores/settings';
 
+	// a #zoom/lat/lng(/bearing/pitch) hash on OUR url is piped through to the
+	// map, so map positions can be bookmarked/shared via ombrella links
+	// (the reverse direction is not possible: the iframe is cross-origin, so
+	// its internal hash changes are unreadable from here)
+	let hashOverride = $state<string | null>(null);
+
+	onMount(() => {
+		const readHash = () => {
+			const hash = window.location.hash;
+			hashOverride = /^#\d+(\.\d+)?\/-?\d+(\.\d+)?\/-?\d+(\.\d+)?/.test(hash) ? hash : null;
+		};
+		readHash();
+		window.addEventListener('hashchange', readHash);
+		return () => window.removeEventListener('hashchange', readHash);
+	});
+
 	// the embedded map understands maplibre's #zoom/lat/lng hash, so the iframe
 	// opens focused on the selected location (zoomed out to regional scale);
 	// picking a new location while on this page recenters the map
 	const iframeSrc = $derived(
-		`https://maps.open-meteo.com/#6/${$storedLocation.latitude.toFixed(3)}/${$storedLocation.longitude.toFixed(3)}`
+		`https://maps.open-meteo.com/${
+			hashOverride ??
+			`#6/${$storedLocation.latitude.toFixed(3)}/${$storedLocation.longitude.toFixed(3)}`
+		}`
 	);
 </script>
 
@@ -18,11 +39,15 @@
 <!-- Full-bleed map: the layout drops its padding for this route. The map
      follows our theme through the color-scheme declared on :root/.dark -->
 <div class="h-full w-full bg-background">
+	<!-- allow="cross-origin-isolated" delegates SharedArrayBuffer use to the
+	     map; it only takes effect when this site itself is served with
+	     COOP/COEP headers (see README, Deployment) -->
 	<iframe
 		src={iframeSrc}
 		title="Open-Meteo Interactive Map"
 		loading="lazy"
 		allowfullscreen
+		allow="cross-origin-isolated"
 		referrerpolicy="no-referrer"
 		class="block h-full w-full border-0"
 		sandbox="allow-scripts allow-same-origin allow-forms allow-popups"