feat(ui,api): strip board redesign - island, rail by day, context view, server search, vault graph

ui/src/routes/system/+layout.svelte

@@ -0,0 +1,32 @@
+<script lang="ts">
+  import { base } from "$app/paths";
+  import { page } from "$app/state";
+  import { isActive, SYSTEM_PAGES } from "$lib/nav";
+  import { cn } from "$lib/utils";
+
+  let { children } = $props();
+</script>
+
+<svelte:head><title>System · Beaver</title></svelte:head>
+
+<div class="min-h-0 flex-1 overflow-y-auto">
+  <div class="mx-auto flex w-full max-w-5xl flex-col gap-6 px-4 py-6 sm:px-6">
+    <nav
+      aria-label="System pages"
+      class="flex flex-wrap items-baseline gap-x-5 gap-y-1"
+    >
+      <h1 class="font-semibold text-lg tracking-tight">System</h1>
+      {#each SYSTEM_PAGES as item (item.href)}
+        {@const active = isActive(page.url.pathname, base, item.href)}
+        <a
+          aria-current={active ? "page" : undefined}
+          class={cn("rule-word", active && "text-foreground")}
+          href="{base}{item.href}"
+        >
+          {item.label}
+        </a>
+      {/each}
+    </nav>
+    {@render children()}
+  </div>
+</div>