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/merge.js

@@ -0,0 +1,26 @@
+import { readFileSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+const submodules = [
+  { name: 'server-core', path: '../server-core/docs/sidebar.json' },
+  { name: 'dashboard-ui', path: '../dashboard-ui/docs/sidebar.json' },
+  { name: 'device-agent', path: '../device-agent/docs/sidebar.json' }
+];
+
+const sidebar = [];
+
+for (const mod of submodules) {
+  const filePath = join(__dirname, mod.path);
+  try {
+    const content = JSON.parse(readFileSync(filePath, 'utf-8'));
+    sidebar.push(content);
+    console.error(`\u2713 Loaded ${mod.name}`);
+  } catch (e) {
+    console.error(`\u26A0 Skipping ${mod.name}: ${e.message}`);
+  }
+}
+
+console.log(JSON.stringify(sidebar, null, 2));