Map-demo is too resource intensive

[ivorbosloper]

If you go to the demo map on a mobile device, it works until you zoom in to the zoom-level where all the different layers become active. Inspecting the mbtiles for all the layers at the same time crashes my browser (default safari on iphone).

Ideally we create a single layer for all available data (112M+ fields)

[cholmes]

An 'all the data' GeoParquet file would also be great to have as well. Ideally we just have a 'merge' command that can point at a set of files, and then combine them all into one.

For this particular use case it could be good to have like a 'latest only' merge where it'd aim to just be the most recent year. But we don't have a ton of that, so probably not needed to get this started.

[ivorbosloper]

If the source parquet datasets are sorted on the same hilbert-curve distance, merging them into a sorted is easy...