fix(docker): never exit the server unless something is known to restart it

#373 restarts the Compose container by exiting the server, which is right for
the shipped deployment: `restart: unless-stopped` relaunches it. The updater
verified that policy through the Docker socket and, when it could not (no
socket mounted), failed open and exited anyway. Failing open is the correct
choice for the GATE, where refusing would block every install without a
socket, but not for the kill: a container the daemon does not restart goes
down for good, with no UI left to recover it from. That is exactly the case a
plain `docker run` of this image without `--restart` produces, and the image
sets CODEMAN_IN_CONTAINER=1 itself, so it takes the container path.

The decision now happens server-side, where both the socket and the Compose
env are reachable, and rides down to the script as `--restart-by-exit 0|1`.
It is 1 when the Compose file declared `CODEMAN_RESTART_BY_EXIT=1` (added there
and only there, since that file is what sets the restart policy; the image ENV
deliberately does not) or when the daemon confirmed an auto-restart policy.
Otherwise the build still lands, the status becomes
`completed-needs-manual-restart` with the `docker restart` hint, and the
server keeps running. The shipped deployment is unchanged in effect: with the
socket it was already confirmed, and without it the declaration now covers it.

Also: a root-run `Start-Codeman.sh` (common on Unraid) created the
fingerprint baseline's `.codeman` directory before the container's first start
and left it root-owned, which the unprivileged server could then never write
its own state into. It is chowned to PUID:PGID when running as root.

Verified with a real image build of the merged tree (classic builder; this
box's BuildKit lacks buildx): runs as uid 1000, tsc/esbuild and the toolchain
present, the four CLIs at their pins, docker/.env absent, and `docker inspect
$HOSTNAME` returns the restart policy through the mounted socket as that user.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qg6bcATm1pNNY4kQWGwzgu

docker/docker-compose.yaml

@@ -20,6 +20,12 @@ services:
       # here. Also set in the image; repeated so a container started without the
       # image default still self-identifies.
       CODEMAN_IN_CONTAINER: "1"
+      # This file sets `restart: unless-stopped` below, so the updater may restart
+      # the server by EXITING. Declared here and only here, never in the image: a
+      # container started by plain `docker run` has no restart policy unless the
+      # operator gave it one, and there the updater asks the daemon instead and
+      # stages the update for a manual restart when it cannot get an answer.
+      CODEMAN_RESTART_BY_EXIT: "1"
       CODEMAN_DOCKER_BRIDGE_HOOKS: ${CODEMAN_DOCKER_BRIDGE_HOOKS}
       # Host-side equivalent of the runtime user's HOME. Docker case seed,
       # credential and hook mounts are translated into the daemon namespace.