Backwards compatible to old chats

src/lib/Chat.svelte

@@ -110,7 +110,7 @@
   <div class="level-left">
     <div class="level-item">
       <p class="subtitle is-5">
-        {chat.name}
+        {chat.name || `Chat ${chat.id}`}
         <a
           href={"#"}
           class="greyscale ml-2 is-hidden editbutton"

src/lib/Sidebar.svelte

@@ -22,7 +22,7 @@
                 class="panel-block {!apiKey ? 'is-disabled' : ''} {activeChatId === chat.id
                   ? 'has-background-light'
                   : ''}"
-                on:click|preventDefault={() => (activeChatId = chat.id)}>{chat.name}</a
+                on:click|preventDefault={() => (activeChatId = chat.id)}>{chat.name || `Chat ${chat.id}`}</a
               >
             </li>
           {/each}