Improve application responsiveness and background processing

src/routes/+layout.svelte

@@ -1,10 +1,10 @@
 <script lang="ts">
     import { onMount } from 'svelte';
     import { startTimeZonePreference } from '$ui/stores/time-zone.js';
-    import { afterNavigate, onNavigate, goto } from '$app/navigation';
+    import { afterNavigate, beforeNavigate, onNavigate, goto } from '$app/navigation';
     import { startPipelineStream } from '$ui/stores/pipeline.js';
     import { startServerStream } from '$ui/stores/servers.js';
-    import { startFleetMonitor } from '$ui/stores/fleet.js';
+    import { startFleetMonitor, hydrateFleet } from '$ui/stores/fleet.js';
     import { page } from '$app/stores';
     import BrandMark from '$ui/components/BrandMark.svelte';
     import Toaster from '$ui/components/Toaster.svelte';
@@ -40,6 +40,8 @@
         else helpOpen = true;
     }
 
+    beforeNavigate(() => performance.mark('ec:navigation-start'));
+    afterNavigate(() => { if (performance.getEntriesByName('ec:navigation-start').length) { performance.measure('ec:navigation', 'ec:navigation-start'); performance.clearMarks('ec:navigation-start'); } });
     afterNavigate(() => { menuOpen = false; accountOpen = false; resolveConfirmation(false); });
 
     function closeMenu(event: KeyboardEvent) {
@@ -67,8 +69,15 @@
         const stopNotifications = startNotificationHistory();
         const stopPipeline = startPipelineStream();
         const stopServers = startServerStream();
-        const stopFleet = startFleetMonitor();
-        return () => { stopNotifications(); stopFleet(); stopPipeline?.(); stopServers?.(); };
+        return () => { stopNotifications(); stopPipeline?.(); stopServers?.(); };
+    });
+
+    $effect(() => {
+        if (!sessionReady) return;
+        const path = $page.url.pathname;
+        if (!(path === '/' || /^\/(servers|scripts|configs|plugins)\//.test(path) || path === '/betas/new')) return;
+        if ('fleetSnapshot' in $page.data && $page.data.fleetSnapshot) hydrateFleet($page.data.fleetSnapshot);
+        return startFleetMonitor();
     });
 
     onMount(() => {