The ground track is cut into polylines so none of them spans 180 degrees, but the
cut only ever appended the outgoing edge point. The next polyline therefore began
at the first sample past the meridian - typically around -178 - so the drawn
track stopped at the edge on one side and reappeared inland on the other,
leaving a visible gap on every orbit that crosses the Pacific.
The edge point also reused the *next* sample's latitude, so the closing leg
jumped: for 179 -> -178 spanning 14 -> 16 degrees latitude the edge was placed at
16.0 instead of the true crossing at 14.667.
Now a crossing closes the current polyline on the edge it leaves through and
opens the next one on the opposite edge, both at the interpolated crossing
latitude, so the seam is continuous.
The split is extracted as the pure internal splitAtAntimeridian/crossingLatitude
pair, which also gives feature:map its first unit tests. Verified against a
standalone Java probe first (eastward, westward, repeated crossings, and a track
hugging the edge without crossing), then as Kotlin tests: restoring the old
single-point behaviour fails four of them, and the current code is green
alongside :core:domain:test and :feature:roaming:testDebugUnitTest.
Also drops the misleading "left/right terminal position" comments: the branch
that fires when the previous sample sat near +180 is the eastward crossing, and
it correctly closes on +180.
mckero
Arty Bishop