feat: web UI chat render, panels, presence + analytics

frontend/src/lib/components/ChatListItem.svelte

@@ -14,7 +14,10 @@
 
   let { chat, selected, onclick }: Props = $props();
 
-  const title = $derived(chat.title ?? `Chat ${chat.chat_id}`);
+  const title = $derived(
+    chat.title ??
+      (chat.chat_id > 0 ? "Удалённый аккаунт" : `Chat ${chat.chat_id}`)
+  );
   const avatarKind = $derived(chat.chat_id > 0 ? "peer" : "chat");
   const ownId = $derived(accounts.selected?.tg_user_id ?? null);
   const showSender = $derived(