feat(serve): HTTP transport + hardened Docker image for secure public serving

Add an opt-in streamable-HTTP transport alongside the default stdio, so
familiar can be reached from a home lab over HTTPS behind a TLS reverse proxy.

- config.http_settings(): env-driven transport/host/port/path/token settings.
- serve.run(): dispatch stdio vs http; fail closed on a non-loopback bind
  without a bearer token (FAMILIAR_ALLOW_INSECURE_BIND escape hatch).
- server.build_http_auth(): FastMCP StaticTokenVerifier bearer gate; add an
  unauthenticated /healthz route for container/proxy probes.
- `familiar serve` CLI alias; clean exit on InsecureBind.
- docker/Dockerfile (multi-stage, non-root) + hardened docker-compose.yml
  (read-only rootfs, cap_drop ALL, no-new-privileges, Traefik TLS labels),
  .dockerignore, .env.example. Token store mounts at /data; writes off by default.
- .gitea/workflows/docker.yml: build + smoke-test, opt-in image publish.
- docs/deployment.md + README/CLAUDE.md notes; tests for settings, fail-closed
  validation, and the bearer verifier.

docker/Dockerfile

@@ -0,0 +1,58 @@
+# syntax=docker/dockerfile:1
+
+# --------------------------------------------------------------------------- #
+# Build stage: build a wheel from the source tree with uv.
+# --------------------------------------------------------------------------- #
+FROM python:3.12-slim AS builder
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PIP_DISABLE_PIP_VERSION_CHECK=1
+
+WORKDIR /app
+
+RUN pip install --no-cache-dir uv
+
+# Files needed to build the wheel (pyproject references README.md + LICENSE).
+COPY pyproject.toml README.md LICENSE ./
+COPY src ./src
+
+RUN uv build --wheel --out-dir /dist
+
+# --------------------------------------------------------------------------- #
+# Runtime stage: minimal, non-root, wheel installed into a clean environment.
+# --------------------------------------------------------------------------- #
+FROM python:3.12-slim
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PIP_DISABLE_PIP_VERSION_CHECK=1 \
+    # HTTP transport, reachable from the proxy network, token-gated.
+    FAMILIAR_TRANSPORT=http \
+    FAMILIAR_HTTP_HOST=0.0.0.0 \
+    FAMILIAR_HTTP_PORT=8000 \
+    FAMILIAR_HTTP_PATH=/mcp \
+    # Token store + audit log + write toggle live here — mount a persistent volume.
+    FAMILIAR_DATA_DIR=/data \
+    # Public instance: writes off by default (smaller blast radius if the token leaks).
+    FAMILIAR_ENABLE_WRITES=false
+
+WORKDIR /app
+
+# Non-root runtime user; /data owned by it so token refresh can write.
+RUN useradd -m -u 1000 -s /usr/sbin/nologin familiar \
+    && mkdir -p /data \
+    && chown -R familiar:familiar /data
+
+COPY --from=builder /dist/*.whl /tmp/
+RUN pip install --no-cache-dir /tmp/*.whl && rm -f /tmp/*.whl
+
+USER familiar
+
+EXPOSE 8000
+VOLUME ["/data"]
+
+HEALTHCHECK --interval=30s --timeout=10s --start-period=10s --retries=3 \
+  CMD python -c "import os,httpx; httpx.get(f\"http://127.0.0.1:{os.environ.get('FAMILIAR_HTTP_PORT','8000')}/healthz\", timeout=5).raise_for_status()" || exit 1
+
+CMD ["familiar", "serve"]