fix(map): Normalize winding order to CCW & replace d3-geo with turf LINDASSUP-247

[hupf]

Closes LINDASSUP-247

• Previously the winding order of polygons has not been modified caused issues with helpers requesting a specific winding order. We now "rewind" the polygons to CCW ("right hand rule"), as is the standard with GeoJSON, right after parsing.
• The d3-geo helpers expected CW winding order, which required a rewinding before every call. Therefore d3-geo is now replaced equivalent helpers from turf, that use the CCW winding order.

How to test

• Create a map visualization for Heavy Metal Soil Contamination: The map should be zoomed to Switzerland, not the whole world (this was the current bug).
• Create a map visualization for Heavy Metal Soil Contamination: The map should (still) be zoomed to Switzerland.
• Symbols on maps should render correctly (how to test?)
• Overlapping smaller regions should be in front of larger regions such they can be hovered and display a tooltip.

---

• I added a CHANGELOG entry
• I made a self-review of my own code
• I wrote tests for the changes (if applicable)
• I wrote configurator and chart config migrations (if applicable)

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Project	Deployment	Actions	Updated (UTC)
visualization-tool	Error		Mar 26, 2026 4:22pm