The toolbar order, favourites, and open panels were saved into
exp_legacy's PlayerData, which was never synced, and the file doing so
was no longer loaded. When a player leaves, the lua side now sends
Gui.toolbar.get_state as json compressed with helpers.encode_string,
and the controller stores the string on the player record.
When the player joins again the instance plugin sends the stored string
over rcon to exp_scenario.player_settings.receive_toolbar, which
decodes it and calls Gui.toolbar.set_state. exp_gui builds the toolbar
in on_player_joined_game, so it exists by the time the rcon arrives.
A string which does not decode, or a state naming buttons which no
longer exist, is logged and ignored rather than raising in the game.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Cooldude2606