Add checked store and set data

src/routes/chat/[chat]/+page.svelte

@@ -1,6 +1,12 @@
 <script lang="ts">
+  import {onMount} from "svelte"
   import {page} from "$app/stores"
   import Chat from "@app/components/Chat.svelte"
+  import {setChecked} from "@app/state"
+
+  onMount(() => {
+    setChecked($page.url.pathname)
+  })
 </script>
 
 <Chat id={$page.params.chat} />