2D CAD custom load visualization

[mimo-to]

Implements a dynamic 2D CAD loading visualization under Additional Inputs → Loading → Custom Load tab.

Implemented Features

Dynamic Load Types

• Point Load: Renders a single downward arrow at the specified x coordinate with custom left-edge dimension lines.
• Line Load: Renders a series of evenly spaced downward arrows connected by a horizontal distribution line spanning from $x_1$ to $x_2$.
• Area Load: Renders a shaded rectangular region with distributed downward arrows covering the loaded span from $x_1$ to $x_2$.

Render Views

• Cross-Section View: Renders the deck thickness, three transverse girders (G1, G2, G3), and load positions.
• Elevation View: Renders the deck and support pylons at both ends to visualize load positions along the longitudinal span length.

UI & Interaction Integration

• Added zoom overlay controls and mouse-wheel scaling.
• Custom load Save/Edit/Delete options.

2D.CAD.custom.load.visualization.and.loading.workflow.mp4