Empty-buffer placeholder for the points node (pre-fetch placeholder).
Constructs a minimal LoadedPointsData inline rather than
routing through createEmptyPointsData() (which needs a full
ProjectionContext with chunkIndex); the values that distinguish
the two paths (ndim, dtypes) are overwritten on the first
successful commit.
Empty-buffer placeholder for the points node (pre-fetch placeholder).
Constructs a minimal LoadedPointsData inline rather than routing through
createEmptyPointsData()(which needs a fullProjectionContextwithchunkIndex); the values that distinguish the two paths (ndim,dtypes) are overwritten on the first successful commit.