Contours layer is a temporary layer (i.e. issue #13 not fixed)

[Ron-Simpson]

A contours_mereged.gpkg file is created by the GUI but it is empty (no tables) and the contours layer is temporary.
A possible cause could be including the field fid in the merge (causes a UNIQUE constraint fail).

An alternate solution (preferable?) would be for the GUI to create a table with all contours rather than separate tables (index, normal and form-line.)

[ryanstocks00]

Whoops, turns out it was more complicated than initially thought. Let's hope this one fixes it https://github.com/Trailblaze-Software/Blaze/actions/runs/22351051406/artifacts/5634696442