[Solessfir]

Mouse support for the desktop UI, split into three commits so each can be reviewed on its own.

Game menus and journal

• Menus use the same input path as touch (Add touch navigation for game menus #1014): left click activates the item under the pointer, sliders can be dragged (with the script step), right click still goes back.
• Hovering selects items. Selection only changes when a different item is hovered, since it runs the item's select commands.
• Hit test: the drawn text wins first, so shared rows such as Back and "More keys" pick the right item; otherwise the script box counts, so short entries (e.g. a one-letter save name) are easy to hit. Boxes without an explicit height use one text line, so neighbouring rows don't overlap. This also makes touch taps between rows more precise.
• Journal: in a category list, hovering a quest highlights it and clicking opens it.
• An arrow pointer is shown while a menu is open.
• In fullscreen, mouse look restarts from the window center after closing a menu, dialogue or inventory, so the camera doesn't jump to where the pointer was left.

Dialogue choices

• Hover highlights a choice, click picks it; clicking beside the choices does nothing. Right click still skips the current line.

Inventories

• Hover selects a cell, left click uses or takes the item; clicking beside the grids does nothing.
• In the player's own inventory, right click on an item drops one (repeating while held, like Space) and Shift+right click drops the stack. Elsewhere right click still closes the inventory.
• While the inventory is open the mouse moves the pointer instead of the camera.

Gothic's [GAME] enableMouse=0 turns all of this off: no pointer, and a click confirms the current selection as before. Touch input does not depend on it.

[Solessfir]

Custom pointer art needs Tempest support first: Try/Tempest#132. Until then this uses the system arrow.