feat(web): add telegram-like message status indicators

- optimistic sending state with pending clock icon

- transition statuses sent -> delivered -> read via realtime events

- render checkmarks next to outgoing message timestamps

web/src/chat/types.ts

@@ -1,5 +1,6 @@
 export type ChatType = "private" | "group" | "channel";
 export type MessageType = "text" | "image" | "video" | "audio" | "voice" | "file" | "circle_video";
+export type DeliveryStatus = "sending" | "sent" | "delivered" | "read";
 
 export interface Chat {
   id: number;
@@ -16,6 +17,9 @@ export interface Message {
   text: string | null;
   created_at: string;
   updated_at: string;
+  client_message_id?: string;
+  delivery_status?: DeliveryStatus;
+  is_pending?: boolean;
 }
 
 export interface AuthUser {