The v0.19.0 regression, its root cause in 223b254, the four decisions
(native landing, narrow-viewport park, jump-back always expands, bottom
workbench keeps its own flows), the change list, and the evidence — including
the environment trap that the PATH `dsh` on this machine is 0.1.2-rc.1 and
cannot register the `file:` tarball into a scratch profile.