[BUG] apply_scale_offset=True with earthdaily.Sentinel2 results in materialized tifs where pixels are all zero and no NoData value

[robmarkcole]

Root cause is a dtype/nodata interaction bug in rslearn materialization, triggered by apply_scale_offset=True

• Sentinel2 scale/offset converts pixels to float reflectance
• During materialization, rslearn force-casts source pixels to the layer band dtype (uint16 in my config)
• If scaled reflectance is in [0, 1), casting to uint16 makes most pixels 0.
• rslearn defaults nodata_vals to 0 when unset
• Output GeoTIFF nodata metadata is not written because encode_raster(...) is called without nodata_val:

So the “all zeros + no nodata” behavior is explained by this chain.

[robmarkcole]

should be fixed