docs: reorganize documentation with i18n and Swagger API reference

- Add per-submodule docs structure (server-core, dashboard-ui, device-agent)
- Restructure VitePress with i18n support (Indonesian default + English)
- Add Swagger API reference pages with Swagger UI CDN embed
- Create merge.js script for combining sidebar manifests
- Integrate docs build into Docker (update.sh + nginx volume mount)
- Add documentation section to root README

docker-compose.yml

@@ -61,6 +61,8 @@ services:
         VITE_API_BASE_URL: ${VITE_API_BASE_URL}
     ports:
       - "${WEB_PORT:-80}:80"
+    volumes:
+      - ./apps/docs/.vitepress/dist:/usr/share/nginx/html/docs:ro
     depends_on:
       - server-core
     restart: unless-stopped