QField already includes an Import datasets tool that copies selected files into the project folder.

On Android, offline basemaps (MBTiles) are shared across projects and must be placed manually in QField/basemaps/. Doing this with external file managers is error-prone and confusing for many users.

I propose adding a very small, minimal feature/plugin, similar to Import datasets, whose only purpose is to copy selected basemap files into QField/basemaps/.

Expected behavior (minimal scope):

Open Android file picker

Select one or more .mbtiles files

Copy them into QField/basemaps/

Handle name collisions (overwrite / rename / skip)

Use temporary .part files during copy to avoid corrupt basemaps

Out of scope:

No downloads or catalogs

No validation or checksums

No automatic project modification

This would keep the core app unchanged, reuse an existing workflow, and make basemap handling on Android safer and easier with very low implementation and maintenance cost.