feat(docker): restore in-app self-update in the Compose deployment

Codeman running under docker/docker-compose.yaml lost the ability to update
itself from App Settings -> Updates. The image had no .git (excluded by
.dockerignore), so the install reported as "unknown"; there was no init system
for detectSupervisor() to find; the runtime stage had neither devDependencies
nor a build toolchain; and a pull into the baked /opt/codeman would have landed
in the container's writable layer and been discarded by the next `up`.

Restore it through configuration rather than a second updater, so the release
channel, auto-stash, status file and boot reconcile are all reused unchanged:

- The checkout Compose builds from is bind-mounted over /opt/codeman, so the
  update's git checkout and rebuild land on the host and survive recreation.
- The restart is the server exiting; `restart: unless-stopped` relaunches the
  container on the new dist/. This is the one supervisor whose updater does NOT
  outlive the restart, which is safe only because the terminal "restarting"
  marker is written first.
- node_modules and dist are named volumes over the bind mount, so
  container-compiled native modules never enter the host checkout.
- The runtime image keeps devDependencies and gains python3/make/g++, since
  `npm run build` is tsc + esbuild and node-pty has no Linux prebuild.

An in-place container update applies code only, because a restart reuses the
existing image and config. evaluateEnvironmentGate() reads the target release's
own files with `git show <tag>:<path>` and refuses when server.Dockerfile or
docker-compose.yaml changed, when .env.example gained keys the user's .env
lacks, or when the restart policy would not bring the container back. The
missing-key check matters most: Compose resolves an unset ${VAR} to the empty
string and starts anyway, so a new required setting would otherwise arrive as a
silently blank variable. Every unknown fails open, and the gate is re-evaluated
server-side on POST /api/system/update.

The four global agent CLIs are pinned, because an unpinned CLI bump is the one
environment change no diff-derived gate can see; pinning turns it into a
Dockerfile change the gate already detects.

Adds test/docker-compose-env-parity.test.ts as the merge-side guard (every
compose ${VAR} has an .env.example entry and the reverse) and
test/docker-self-update.test.ts for the pure gate decisions.

Documented in docs/docker-self-update.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013yAQ2y9t81jzSfpStUxx5T

docker/Start-Codeman.sh

@@ -70,4 +70,54 @@ fi
 
 export DOCKER_SOCKET_GID=${socket_ids##*:}
 
+repo_path=${CODEMAN_REPO_PATH:-$(cd -- "$script_dir/.." && pwd)}
+if [[ ! -d "$repo_path" ]]; then
+  printf 'Error: CODEMAN_REPO_PATH is not a directory: %s\n' "$repo_path" >&2
+  exit 1
+fi
+export CODEMAN_REPO_PATH="$repo_path"
+
+# The in-app updater runs `git checkout` and `npm install` against this checkout
+# as PUID:PGID. If the directory belongs to someone else, git refuses outright
+# ("detected dubious ownership") and the update fails at the first step — so warn
+# here, where the fix is obvious, rather than in a failed update hours later.
+if repo_owner=$(stat -c '%u' -- "$repo_path" 2>/dev/null || stat -f '%u' "$repo_path" 2>/dev/null); then
+  if [[ "$repo_owner" != "$PUID" ]]; then
+    printf 'Warning: %s is owned by UID %s but Codeman runs as UID %s.\n' "$repo_path" "$repo_owner" "$PUID" >&2
+    printf 'In-app updates will fail until the ownership matches. Codeman itself still starts.\n' >&2
+  fi
+fi
+
+if [[ ! -d "$repo_path/.git" ]]; then
+  printf 'Note: %s is not a git checkout, so in-app updates are unavailable.\n' "$repo_path" >&2
+fi
+
+# Record what the container is about to be built and created FROM. The in-app
+# updater compares these against the release it wants to apply: a release that
+# changes either file cannot be applied by the container restarting itself (a
+# restart reuses the existing image and config), so it is refused and the user
+# is sent back here. Written on every start, so the baseline always describes
+# the container that is actually running. See docs/docker-self-update.md.
+if command -v sha256sum >/dev/null 2>&1; then
+  sha256_of() { sha256sum -- "$1" | cut -d' ' -f1; }
+elif command -v shasum >/dev/null 2>&1; then
+  sha256_of() { shasum -a 256 -- "$1" | cut -d' ' -f1; }
+else
+  sha256_of() { printf ''; }
+fi
+
+dockerfile_sha=$(sha256_of "$script_dir/server.Dockerfile")
+compose_sha=$(sha256_of "$compose_file")
+if [[ -n "$dockerfile_sha" && -n "$compose_sha" ]]; then
+  # $CODEMAN_APPDATA_PATH is mounted at the runtime account's home, so this is
+  # dataPath('docker-env-applied.json') as the server inside the container sees it.
+  state_dir="$appdata_path/.codeman"
+  mkdir -p -- "$state_dir"
+  printf '{\n  "dockerfileSha256": "%s",\n  "composeSha256": "%s"\n}\n' \
+    "$dockerfile_sha" "$compose_sha" >"$state_dir/docker-env-applied.json.tmp"
+  mv -- "$state_dir/docker-env-applied.json.tmp" "$state_dir/docker-env-applied.json"
+else
+  printf 'Warning: no sha256 tool found; in-app updates will not detect environment changes.\n' >&2
+fi
+
 exec docker compose --env-file "$env_file" -f "$compose_file" up --build -d