fix chatgui: members showing offline after JOIN — always refresh channel cache before posting online count

tools/chatgui/transport/chat_sync.c

@@ -1259,12 +1259,8 @@ static void cs_handle_channel_join(struct chat_sync* cs, uint64_t peer,
         cs_propagate(cs, ch_id, peer, ubuf, uoff);
     }
 
-    /* add to channel cache */
-    struct channel_cache* ch = cs_find(cs, ch_id);
-    if (!ch) {
+    /* add to channel cache — always refresh to include new peer */
     cs_refresh_channels(cs);
-        ch = cs_find(cs, ch_id);
-    }
 
     { uint8_t evt[65]; uint8_t cl=(uint8_t)strlen(ch_id); evt[0]=cl; memcpy(evt+1,ch_id,cl);
       gui_bridge_post(GUI_EVT_MEMBERS_CHANGED, evt, 1+cl); }