The previous commit stopped the panel header from colliding with the "Assets"
heading, but left the search box sharing a row with the type dropdown: 139px of
input for a placeholder needing 216px, so it still read "Search name o". A
control whose own label does not fit is not a narrower control, it is an
unlabelled one.
One control per row in a 318px panel. Measured in the browser: the input is now
286px against 216px of text, so the placeholder reads in full.
afd3dce493