feat: one gateway port with path-mounted frontends, markdown chat, collapsible sidebars

ui/src/lib/components/conversation-list.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import PanelLeftCloseIcon from "@lucide/svelte/icons/panel-left-close";
   import PlusIcon from "@lucide/svelte/icons/plus";
   import { toast } from "svelte-sonner";
   import { goto } from "$app/navigation";
@@ -17,6 +18,7 @@
   import { clip, fmtRelative, shortId } from "$lib/format";
   import { gateway } from "$lib/gateway.svelte";
   import { session } from "$lib/session.svelte";
+  import { ui } from "$lib/ui.svelte";
   import { cn } from "$lib/utils";
 
   let { selected = null }: { selected?: string | null } = $props();
@@ -162,6 +164,16 @@
     <Button aria-label="New conversation" onclick={openCreate} size="icon-sm">
       <PlusIcon class="size-4" />
     </Button>
+    <Button
+      aria-label="Hide conversations"
+      class="hidden lg:inline-flex"
+      onclick={() => ui.toggleRail()}
+      size="icon-sm"
+      title="Hide conversations"
+      variant="ghost"
+    >
+      <PanelLeftCloseIcon class="size-4" />
+    </Button>
   </div>
   <div class="min-h-0 flex-1 overflow-y-auto">
     {#if gateway.live.state === "failed"}