When DiscordAdapter.connect() is called during reconnect, it creates a new
commands.Bot client without closing the previous one. The old client's
websocket remains connected to Discord's gateway, causing both to fire
on_message for every incoming event — resulting in double responses.
Fix: before creating a new Bot instance, check if a previous client exists
and close it. This ensures only one websocket connection is active at any
time.
Closes#18187