Retain host and server scope during investigations

src/routes/hosts/[id]/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+    import { contextHref } from '$lib/navigation-context.js';
     import { untrack } from 'svelte';
     import { pollVisible } from '$ui/poll.js';
     let requestSequence = 0;
@@ -57,7 +58,7 @@
 
 <svelte:head><title>{host?.name ?? 'Host'} · Electric Cherry</title></svelte:head>
 <section class="page"><a href="/hosts">← All hosts</a><SectionHeader title={host?.name ?? 'Host'} subtitle="Running instances, readiness, inventory, settings, and credentials.">
-    {#snippet actions()}<Button href="/hosts/operations">Operation history</Button>{#if canManage && host && (!cleaning || host.decommission?.retryable)}<Button variant="danger" disabled={busy} onclick={() => deleteOpen = true}>{cleaning ? 'Retry cleanup' : 'Delete host'}</Button>{/if}{/snippet}
+    {#snippet actions()}<Button href={contextHref(`/capacity?host=${encodeURIComponent($page.params.id ?? "")}`, $page.url)}>Capacity</Button><Button href={contextHref(`/hosts/operations?host=${encodeURIComponent($page.params.id ?? "")}`, $page.url)}>Operation history</Button>{#if canManage && host && (!cleaning || host.decommission?.retryable)}<Button variant="danger" disabled={busy} onclick={() => deleteOpen = true}>{cleaning ? 'Retry cleanup' : 'Delete host'}</Button>{/if}{/snippet}
 </SectionHeader>
     {#if error}<p class="ui-error" role="alert">{error}</p>{/if}{#if notice}<p role="status">{notice}</p>{/if}
     {#if loading}<p role="status">Loading host…</p>{:else if host}