Assistant bangs without text should redirect to the specified mode

Value7609

Steps to reproduce:
type e.g. "!expert" (without a prompt/query), it will redirect to /assistant and it will open your default mode.
Same thing for the other AI bangs

Expected behavior:
open /assistant?mode=7&sub_mode=2

Debug info:
Firefox 118/Linux

Reroute5183

Same with other modes like !expert, !fast, etc.