Preserve deleted server history

Retain historical server identities, results, and evidence after deletion. Mark archived entries as Deleted and prevent old work from targeting servers that reuse the same name.

Fixes #16.

src/lib/ui/components/HistoricalServerIdentity.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+    import ServerIdentity from './ServerIdentity.svelte';
+    import Badge from './primitives/Badge.svelte';
+
+    let { name, deletedAt, href }: { name: string; deletedAt?: string | null; href?: string } = $props();
+</script>
+
+<span class="historical-server">
+    {#if href && !deletedAt}<a {href}><ServerIdentity {name} /></a>
+    {:else}<ServerIdentity {name} />{/if}
+    {#if deletedAt}<Badge>Deleted</Badge>{/if}
+</span>
+
+<style>
+    .historical-server { display: inline-flex; align-items: baseline; flex-wrap: wrap; gap: 6px 8px; min-width: 0; }
+    a { color: var(--accent-primary-hover); }
+</style>