fix: correct ELLIPSE marker size to match in-game display

[fank]

Summary

• Fixes ELLIPSE markers being rendered larger than their in-game size
• ELLIPSE markers now use the same coordinate conversion as RECTANGLE markers

Problem

ELLIPSE markers used an arbitrary calculation:

let rad = this._size[0] * 0.015 * window.multiplier;

This magic number 0.015 didn't correctly convert Arma meters to Leaflet map units, resulting in markers appearing larger than in-game.

Additionally, only size[0] was used, making all ellipses circular regardless of their actual dimensions.

Solution

Changed ELLIPSE to use the same approach as RECTANGLE:

1. Calculate perimeter points in Arma coordinates (meters)
2. Convert each point via armaToLatLng()
3. Apply rotation using existing _rotatePoints() method
4. Render as L.polygon instead of L.circle

This ensures ellipses:

• Match their in-game size exactly
• Support true ellipse shapes (different X and Y radii)
• Support rotation (marker direction)

Test plan

• Load a recording with ELLIPSE markers
• Compare marker size in web replay vs in-game screenshot
• Verify ellipse rotation works correctly
• Verify ellipse opacity/alpha works correctly