Fixed Camera elevation is often underground when moving it with "C" key

[Mick West]

Moving rapidly around with the C key seems to sometimes miss the elevation data, even when the visible geometry is elevated.

This seems to occur when terrain is still being processed. Maybe async web-worker bug.

Possibly unrelated, even after loading, visible geometry and reported elevation don't match on steep and varied terrain

https://local.metabunk.org/sitrec/?...G _ elevation under ground/20251110_171731.js