App names may now contain dots, such as sneak.berlin: runs of
lowercase letters and numbers joined by single dots or by hyphens,
2 to 63 characters. Docker accepts every such name in the app's image
name, upaas-<name>; a dot needs a letter or number on both sides
because Docker requires it. The rule also keeps a dot off either end,
so the name is safe as a directory and log file name.
The new and edit app forms use the same pattern. Their old one was not
a valid regular expression under the flag browsers compile it with, so
browsers ignored it.
Model: opus-5-5
