raise() could send a claim to the BACK. Each claim owned a fixed offset, so on a
nearly-full rung there was no free slot above the top and the fallback took the
lowest free one instead: a floating window clicked to front went behind its
peers. Only reachable once a rung fills, which is a long session, not a test.
A rung is now an ordered list and z is derived from position, so raise() is a
move to the end and release() compacts.
drag.js shipped with no tests. 12 now, including the ones that matter: a second
pointer cannot hijack a drag, capture is released on cancel, and dispose stops a
drag already in progress.
digital-garbage
0e842d1666