Codex re-gate found the single-row resize fast path used parseFloat on
getComputedStyle(el).minHeight, which reads a bogus pixel value for a
non-px unit (parseFloat('50%')===50) and would wrongly enable the fast
path, leaving an oversized composer stuck tall. Parse with a strict
/^<number>px$/ test so %, auto, empty, and calc() fail closed to the
full resize. Adds red-before-green regression coverage across units.
Co-authored-by: sheldon-im <sheldon-im@users.noreply.github.com>
