Previously, DIVE would error when importing stereo or multicamera data
where images in different directories had the same filenames (e.g.,
left/image001.png and right/image001.png). This is a valid use case
for stereo camera setups.

The fix modifies the overlap validation in ImportMultiCamDialog.vue to
only check for duplicate filenames in keyword/glob mode (where images
come from a single shared directory). In multi-folder mode, same
filenames in different directories are now allowed since each camera
has its own source directory.