feat(deploy): serve SPA from server, Dockerfile, compose, deploy docs

- Add serveStatic middleware to server/src/app.ts to serve web/dist
- Include SPA fallback route for client-side routing deep links
- Create Dockerfile with multi-stage build (Node deps + build, slim runtime)
- Add docker-compose.yml for single-command deployment
- Add docs/deploy.md with deployment instructions and Caddy reverse proxy example
- Add bun run build:web step to CI pipeline after typecheck

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,16 @@
+FROM oven/bun:1 AS build
+WORKDIR /app
+COPY package.json bun.lock* ./
+COPY server/package.json server/
+COPY web/package.json web/
+COPY shared/package.json shared/
+RUN bun install --frozen-lockfile
+COPY . .
+RUN bun run build:web
+
+FROM oven/bun:1-slim
+WORKDIR /app
+COPY --from=build /app /app
+ENV DATA_DIR=/data
+EXPOSE 3000
+CMD ["bun", "server/src/index.ts"]