feat(paseo): preinstall nano and set the git identity from the environment

GIT_NAME and GIT_EMAIL expand into the four GIT_AUTHOR_*/GIT_COMMITTER_*
variables, the same shape code-server already uses. Passing the identity as
environment rather than running `git config` means agents and terminals commit
correctly with no setup step, and it does not depend on ~/.gitconfig surviving
in the /home/paseo volume.

paseo/Dockerfile

@@ -11,7 +11,7 @@ FROM ghcr.io/getpaseo/paseo:latest
 # not, despite Debian's base-passwd shipping an (empty) sudo group.
 RUN apt-get update \
  && apt-get install -y --no-install-recommends \
-      less jq unzip zip lsof psmisc ugrep bfs zsh sudo \
+      less nano jq unzip zip lsof psmisc ugrep bfs zsh sudo \
  && rm -rf /var/lib/apt/lists/* \
  && usermod -aG sudo paseo