The first sftp connection now lists ~/.ssh before it fetches
authorized_keys. The file reads as empty in just two cases: sftp reports
~/.ssh itself as not there, or the listing succeeds and the fetch then
reports the file as not there. A directory that is there but cannot be
entered, or a file that cannot be read, fails the run and writes nothing,
so a ~/.ssh whose mode shuts the user out is no longer read as a host
with no file and replaced by one holding the new key alone. The write
connection makes ~/.ssh and sets 0700 only when the read found none; an
existing directory keeps its mode.
Model: opus-4-8
