feat: add docs Dockerfile for containerized hosting

apps/docs/Dockerfile

@@ -0,0 +1,21 @@
+FROM oven/bun:1.3.14-alpine AS builder
+
+# git is required by VitePress lastUpdated (reads commit timestamps)
+RUN apk add --no-cache git
+
+WORKDIR /app
+
+COPY apps/docs/package.json ./package.json
+RUN bun install
+
+COPY apps/docs/ ./
+RUN bun run build
+
+FROM nginx:alpine AS runner
+
+COPY --from=builder /app/.vitepress/dist /usr/share/nginx/html
+COPY apps/docs/nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]