git: Keep the cgit image away from gitolite's ~/.ssh.

The image's sshd setup runs chown -R on $S6_USERHOME/.ssh, which was
gitolite's .ssh on the shared volume, and broke gitolite.  Give cgit's
user a home inside the container and set PUID to that user so its key
generation succeeds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Change-Id: I67527fba73527fc71b87aac876ec1ea09860c76b
1 file changed