правки

tg_parser/internal/adapter/telegram/get_channel_diff.go

@@ -95,7 +95,8 @@ func extractChannelMeta(currentChannel domain.Channel, chats []tg.ChatClass) *do
 			continue
 		}
 
-		username := ""
+		// Preserve username if Telegram doesn't provide a new one (private channels may not have username)
+		username := currentChannel.Username
 		if usernameVal, ok := ch.GetUsername(); ok && usernameVal != "" {
 			username = usernameVal
 		}
@@ -112,6 +113,7 @@ func extractChannelMeta(currentChannel domain.Channel, chats []tg.ChatClass) *do
 			Username:     username,
 			Title:        ch.Title,
 			AccessHash:   accessHash,
+			InviteLink:   currentChannel.InviteLink, // Preserve invite link (never returned in channel diff)
 			Pts:          currentChannel.Pts,
 			IsAccessible: currentChannel.IsAccessible,
 		}