Army panel reset and river editing improvements

Army panel reset with a unified style.

River editing improved: you can now multi-select control points and a button was added to delete all rivers.

The new river editing workflow is as follows:

Left-click to select a river.

• Drag a box with the left mouse button to select river control points.

• Hold the left mouse button to drag selected control points.

• Alt + left-click to add a new control point.

• Shift + left-click to create a new river.

• Delete removes control points; if none are selected the entire river is deleted.

Bug fixes:

• Fixed rivers becoming unselectable after dragging control points.

• Fixed some legacy maps losing their religions.

• Fixed countries failing to elect a new leader after the previous one died.

• Fixed right-click movement sometimes failing in RTS mode.

• Fixed incorrect naming and description when creating new religions.

• Fixed the memory leak caused by storing historical national borders.

• Fixed duplicate trait labels in the character panel.

• Fixed province names changing when renaming a rebellious country.

• Fixed armies getting stuck on desert, Gobi, tundra, and similar borders.

• Fixed incorrect latitude display in the editing interface.

• Fixed the map latitude not refreshing promptly.

• Fixed deleted cities reappearing after exporting the map.