[WIP] Change rectangle shape generator from spiral to zig-zag column construction pattern

[Copilot]

Change the rectangle construction sequence from a spiral pattern (wrapping outward from center) to a zig-zag column-extension pattern (building columns left-to-right with alternating vertical direction).

Status: Analysis only — no code changes implemented.

Desired Pattern

Current (spiral):          Desired (zig-zag):
9---10...                  4---5---6
|    |                     |   |   |
8---1---2                  3---2---7---10
|   |   |                  |   |   |    |
7---0---3                  0---1---8---9
|   |   |
6---5---4

Analysis

• Angle sequence derived from diagram: 0, 90, 90, -90, -90, 0, -90, 0, 90, 90, 0, ... (spiral uses +90 for all turns)
• numAdditionalConnections: 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, ...
• Files requiring changes: CudaShapeGenerator.cuh (CUDA-side) and ShapeGenerator.cpp (CPU-side)

Remaining Work

• Verify angle sign convention via ObjectDesc::getAngleSpan()
• Determine vertical growth strategy (fixed height vs expanding)
• Implement both CPU and CUDA generators with matching logic
• Compute requiredNodeId1/requiredNodeId2 tracking for CUDA side
• Validate against existing ConstructorTests_AllShapes parameterized tests

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