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

apps/docs/id/api/index.md

@@ -0,0 +1,31 @@
+# Referensi API NexusGuard
+
+Halaman ini menyediakan dokumentasi interaktif untuk API Server Core NexusGuard.
+
+<div id="swagger-ui"></div>
+
+<script setup>
+import { onMounted } from 'vue'
+
+onMounted(() => {
+  const script = document.createElement('script')
+  script.src = 'https://unpkg.com/swagger-ui-dist@5/swagger-ui-bundle.js'
+  script.onload = () => {
+    window.SwaggerUIBundle({
+      url: '/server-core/docs/swagger.json',
+      dom_id: '#swagger-ui',
+      presets: [
+        window.SwaggerUIBundle.presets.apis,
+        window.SwaggerUIBundle.SwaggerUIStandalonePreset
+      ],
+      layout: 'BaseLayout'
+    })
+  }
+  document.head.appendChild(script)
+  
+  const link = document.createElement('link')
+  link.rel = 'stylesheet'
+  link.href = 'https://unpkg.com/swagger-ui-dist@5/swagger-ui.css'
+  document.head.appendChild(link)
+})
+</script>