Vertical Plane Camera Navigation

Added support for camera movement along the ZX plane using the middle mouse button. This is especially helpful while moving up and down along tall structures and building facades.
Improved: Divider Styling with Custom Material

Replaced UMG borders with a custom material to enhance visual quality, styling, and flexibility for slim UI dividers. Unreal Engine’s default borders often appeared pixelated when used with narrow elements. The new material resolves this issue and supports real-time control over sharpness, color gradients, and dynamic adjustments during play.