Add FastAPI web/API layer and static site

- queries.py: shared read-only query helpers (feed, brief, category counts)
  returning plain dicts, used by the API and available to the CLI.
- api.py: FastAPI service with Pydantic response models (the companion-app
  contract), CORS, and endpoints for categories, feed, brief, and health;
  mounts a static site at /.
- static/index.html: minimal dependency-free site rendering the daily five
  and topic/flavor category browsing.
- 'goodnews serve' command launches uvicorn (lazy import; core CLI stays
  pure-stdlib). Web deps live behind the optional [web] extra.
- Dockerfile + .dockerignore + build-system metadata so the service installs
  and deploys cleanly, with the DB mounted as a shared volume.
- README: web/API and deployment docs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,21 @@
+# goodNews web/API image.
+#
+# The SQLite database is NOT baked into the image — mount it at /data so the API
+# and the ingestion CLI (run separately, e.g. via cron on the host) share one
+# file. Build:  docker build -t goodnews .
+# Run:    docker run -p 8000:8000 -v /srv/goodnews/data:/data goodnews
+FROM python:3.13-slim
+
+WORKDIR /app
+
+# Install dependencies first for better layer caching.
+COPY pyproject.toml README.md ./
+COPY goodnews ./goodnews
+RUN pip install --no-cache-dir ".[web]"
+
+# API reads the database from here; mount a host dir or named volume.
+ENV GOODNEWS_DB=/data/goodnews.sqlite3
+VOLUME ["/data"]
+
+EXPOSE 8000
+CMD ["uvicorn", "goodnews.api:app", "--host", "0.0.0.0", "--port", "8000"]