Add back button to chat detail

src/app/components/Chat.svelte

@@ -34,6 +34,7 @@
     messagingRelayListsByPubkey,
   } from "@welshman/app"
   import Danger from "@assets/icons/danger-triangle.svg?dataurl"
+  import ArrowLeft from "@assets/icons/arrow-left.svg?dataurl"
   import Icon from "@lib/components/Icon.svelte"
   import Spinner from "@lib/components/Spinner.svelte"
   import PageBar from "@lib/components/PageBar.svelte"
@@ -72,6 +73,8 @@
       ? pushModal(ProfileDetail, {pubkey: others[0]})
       : pushModal(ChatMembers, {pubkeys: others})
 
+  const back = () => history.back()
+
   const replyTo = (event: TrustedEvent) => {
     parent = event
     compose?.focus()
@@ -251,6 +254,10 @@
 </script>
 
 <PageBar>
+  <div class="flex">
+    <Button onclick={back} class="place-self-start pr-3 md:hidden flex items-center">
+      <Icon icon={ArrowLeft} size={7} />
+    </Button>
     <div class="flex items-center justify-between gap-4">
       <div class="ellipsize flex items-center gap-4 whitespace-nowrap">
         <Button class="flex flex-col gap-1 sm:flex-row sm:gap-2" onclick={showMembers}>
@@ -282,6 +289,7 @@
         </Button>
       </div>
     </div>
+  </div>
 </PageBar>
 
 <PageContent class="flex flex-col-reverse gap-2 pt-4">