The agent as a container image (M1.5)

- Dockerfile: built with uv into /opt/nisse (installed, not editable),
  run on python:3.12-slim with openssh-client as user nisse; stateless,
  with state in a /var/lib/nisse-dev volume, config mounted at
  /etc/nisse-dev/nisse-dev.yaml, secrets as environment variables, keys
  mounted read-only. 202 MB. Its `test` stage adds the tests and their
  tools over the installed package (UV_NO_SYNC, so `uv run` never swaps
  in the source tree); the default target is the agent.
- scripts/e2e.sh --image REF runs the suite inside an image's test stage,
  on its own sshd.
- CI builds both images on every PR (nothing pushed); release.yml pushes
  gitea.dongar.net/dongar/nisse-dev:<tag> and :latest on a v* tag, with
  the REGISTRY_TOKEN secret.
- scripts/bringup.sh builds the code under test into an image and runs it
  in the systemd unit (root, $E2E mounted at its own path); `plan` prints
  what it would run; the build-VM set-aside reads the projects: config.

Checked: the image refuses to start without a config, runs as uid 10001;
one e2e test passed from the test stage (2m45s, $0).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

.gitea/workflows/ci.yml

@@ -55,6 +55,20 @@ jobs:
           NISSE_OPERATOR_TOKEN: ${{ secrets.NISSE_OPERATOR_TOKEN }}
         run: uv run pytest -m "integration and not e2e" -rs
 
+  image:
+    # The agent's image builds (Dockerfile), so a broken one shows before a
+    # release does. On PRs only; nothing is pushed.
+    if: github.event_name != 'push'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build the agent and test images
+        run: |
+          docker build --target agent -t nisse-dev:ci .
+          docker build --target test -t nisse-dev:ci-test .
+          docker run --rm nisse-dev:ci 2>&1 | grep -q "cannot start: no config file"
+
   e2e:
     # The end-to-end suite (scripts/e2e.sh): the whole agent against real
     # services, every role on a local model, so it spends nothing but keeps