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

ui/src/lib/components/page-header.svelte

@@ -0,0 +1,44 @@
+<script lang="ts">
+  import type { Snippet } from "svelte";
+  import LiveDot from "$lib/components/live-dot.svelte";
+  import { gateway } from "$lib/gateway.svelte";
+
+  let {
+    title,
+    subtitle = "",
+    children,
+    actions,
+  }: {
+    title: string;
+    subtitle?: string;
+    children?: Snippet;
+    actions?: Snippet;
+  } = $props();
+</script>
+
+<header
+  class="flex min-h-12 flex-wrap items-center gap-x-4 gap-y-2 border-b px-4 py-2 sm:px-6"
+>
+  <div class="flex min-w-0 items-baseline gap-2">
+    <h1 class="truncate font-semibold text-lg tracking-tight">{title}</h1>
+    {#if subtitle}
+      <span class="truncate text-muted-foreground text-sm">{subtitle}</span>
+    {/if}
+  </div>
+  {#if children}
+    <div class="flex min-w-0 flex-wrap items-center gap-2">
+      {@render children()}
+    </div>
+  {/if}
+  <div class="ml-auto flex items-center gap-2">
+    {#if actions}
+      {@render actions()}
+    {/if}
+    <LiveDot
+      class="sm:hidden"
+      detail={gateway.live.detail}
+      label={false}
+      state={gateway.live.state}
+    />
+  </div>
+</header>