First of all, Thanks for cool UI.

I'm new in jj and jjui, I can't remember all the shortcuts, so I always end up looking at the help. (maybe 100+ times per day)
but if the rev-log contains multi-byte characters (like Japanese), the dialog (help, bookmark operations, git operations, ...) will be distorted.
(Preview is fine, it effect center-positioned dialogs only)

Originally posted by @cocoich in #129