GUI: An option to decrease transparency/increase opacity of log area (and maybe Hotkeys one too)

This would greatly increase readability:


Hotkeys area is less of an issue thanks to game using very bright font color there

Start by locating the GUI code responsible for rendering the log area and, if applicable, the Hotkeys area; the issue provides no file or test entry point. Review how transparency is currently configured, then verify that users can control the log area's opacity and that the resulting text is more readable.

Written by the indexing model from the issue text.