Consider reversing diff

When the tool detects that it would overwrite an existing file with a version from the module template and you choose to see the differences between the two, the diff appears to indicate the opposite: that you have a version from the module template and you want to apply your version on top of it. Should the diff be reversed?

Start by tracing the tool's overwrite-existing-file flow and the path used to display differences between the module template and the existing file. Reproduce the reported case, then verify that the diff labels and orientation correctly show which version would overwrite the other.

Written by the indexing model from the issue text.