ChatPlus 1.4.1 — chat button opacity fix

Fixes the chat opacity slider for the controls added by ChatPlus: the settings button, gear icon and resize handle now fade together with the chat background.

Message text and selection highlighting keep their opacity. Button hit areas remain usable while the native chat is active. Existing settings and history are preserved.

Validation: release build completed with no warnings or errors; 648 automated checks passed. No additional in-game test was performed for this patch.