feat(ui,api,admin): sveltekit admin spa, usage by day/agent/conversation/model, rate limits, memory tree, turn snapshot

ui/src/routes/conversations/[id]/+page.svelte

@@ -0,0 +1,23 @@
+<script lang="ts">
+  import { goto } from "$app/navigation";
+  import { base } from "$app/paths";
+  import { page } from "$app/state";
+  import ConversationView from "$lib/panel/conversation-view.svelte";
+  import { session } from "$lib/session.svelte";
+
+  const id = $derived(page.params.id ?? "");
+  const href = (target: string) => `${base}/conversations/${target}`;
+</script>
+
+<svelte:head><title>Conversation · Beaver</title></svelte:head>
+
+{#if session.client && id}
+  {#key id}
+    <ConversationView
+      client={session.client}
+      {href}
+      {id}
+      onOpen={(target) => goto(href(target))}
+    />
+  {/key}
+{/if}