created auth system

src/app/models/auth.model.ts

@@ -0,0 +1,20 @@
+export interface AuthSession {
+  sessionId: string;
+  telegramUserId: number;
+  username: string | null;
+  displayName: string;
+  active: boolean;
+  expiresAt: string;
+}
+
+export interface TelegramAuthData {
+  id: number;
+  first_name: string;
+  last_name?: string;
+  username?: string;
+  photo_url?: string;
+  auth_date: number;
+  hash: string;
+}
+
+export type AuthStatus = 'unknown' | 'checking' | 'authenticated' | 'expired' | 'unauthenticated';