Codex review flagged that /tmp/a.png ./b shot.png slipped past the
interior-anchor guard (absolute prefixes only) and fused into one bogus
attach that swallows the paste. Add ./, ../ and .\ as second-path
anchors; bare relatives (dir/b shot.png) stay recoverable because an
interior token/ after a space is exactly the shape of a spaced
directory name (/Users/me/My Photos/shot 1.png). 4 tests pin both
sides of the boundary.