Support BigTiff export

802.9962 [tiff_open] error: TIFFAppendToStrip: Maximum TIFF file size exceeded
802.9984 [tiff_open] error: TIFFWriteDirectoryTagData: Maximum TIFF file size exceeded
805.0866 [imageio_storage_disk] could not export to file: `/Users/ben/Pictures/darktable_exported/img20260302_20561413_01.tif'!

I am on macos 23 or 24, whatever tahoe is. My libtiff should support bigTiff. The image that i'm trying to export is going be larger than 4gb. It wouldn't be hard to calculate the size of the image and automatically use bigtiff if is supported.

Describe the solution you'd like
I would like to export a tiff file and have it use bigtiff if the file is larger than 4gb. Idealy this would be automatic. Otherwise, I would hope for a tiff export, enable BigTiff, realize it doesn't have all of the features that tiff might, and live with the results.

Alternatives
I would love a way to export a tiff file even without all of the options of a standard tiff. Ideally, this would just work but I realize this is an edge case. I'm happy to provide images and test out features using a dev branch.

Additional context
It appears that my libtiff supports BigTiff. It also appears that darktable does not leverage this. It would be really nice if you were to throw up the error message or something that states the image is too large for a tiff export and perhaps provide a way around it or an appropriate file format that is lossless like a tiff.

The report names the TIFF export path (imageio_storage_disk) and libtiff errors; start by tracing that export path and checking how BigTIFF support is exposed. Done means exports over 4 GB succeed when supported, or a clear fallback or error is presented for files that exceed standard TIFF limits.