media: make all media direct downloadable

The only exception is emojis.

Also changed direct download encoding field names to be more generic
when used in mixed manner depending on peer type.

Direct downloads are still somewhat inefficient as they require an API
round trip to succeed but we can cache things in the database if needed.

pkg/connector/sync.go

@@ -149,6 +149,22 @@ func (t *TelegramClient) handleDialogs(ctx context.Context, dialogs tg.ModifiedM
 					Msg("Not syncing portal because chat type is unsupported")
 				continue
 			}
+			fullChat, err := APICallWithUpdates(ctx, t, func() (*tg.MessagesChatFull, error) {
+				return t.client.API().MessagesGetFullChat(ctx, chat.GetID())
+			})
+			if err != nil {
+				log.Err(err).Msg("Failed to get full chat")
+				continue
+			}
+			chatFull, ok := fullChat.FullChat.(*tg.ChatFull)
+			var avatar *bridgev2.Avatar
+			if ok {
+				avatar, err = t.convertPhoto(ctx, ids.PeerTypeChat, chatFull.ID, chatFull.ChatPhoto)
+				if err != nil {
+					log.Err(err).Msg("Failed to convert group avatar")
+				}
+			}
+
 			chatInfo = &bridgev2.ChatInfo{
 				CanBackfill: true,
 				Name:        &chat.(*tg.Chat).Title,
@@ -161,6 +177,7 @@ func (t *TelegramClient) handleDialogs(ctx context.Context, dialogs tg.ModifiedM
 						},
 					},
 				},
+				Avatar: avatar,
 			}
 		case *tg.PeerChannel:
 			channel := chats[peer.ChannelID]
@@ -176,6 +193,14 @@ func (t *TelegramClient) handleDialogs(ctx context.Context, dialogs tg.ModifiedM
 					Msg("Not syncing portal because channel type is unsupported")
 				continue
 			}
+			fullChannel := channel.(*tg.Channel)
+			var avatar *bridgev2.Avatar
+			if photo, ok := fullChannel.GetPhoto().(*tg.ChatPhoto); ok {
+				avatar, err = t.convertChatPhoto(ctx, fullChannel.ID, fullChannel.AccessHash, photo)
+				if err != nil {
+					log.Err(err).Msg("Failed to convert channel avatar")
+				}
+			}
 			chatInfo = &bridgev2.ChatInfo{
 				CanBackfill: true,
 				Name:        &channel.(*tg.Channel).Title,
@@ -188,6 +213,7 @@ func (t *TelegramClient) handleDialogs(ctx context.Context, dialogs tg.ModifiedM
 						},
 					},
 				},
+				Avatar: avatar,
 				ExtraUpdates: func(ctx context.Context, p *bridgev2.Portal) bool {
 					return p.Metadata.(*PortalMetadata).SetIsSuperGroup(channel.(*tg.Channel).GetMegagroup())
 				},