feat: add layout components and pages for NxMesh Admin

- Implemented Header, Sidebar, and Layout components for consistent UI structure.
- Created pages for Agents, Certificates, Configurations, Dashboard, and Settings.
- Integrated React Query for data fetching in Agents, Certificates, Configurations, and Dashboard pages.
- Added Tailwind CSS for styling and responsive design.
- Established a utility function for conditional class names.
- Set up Vite configuration for React project with TypeScript support.
- Included global styles and Tailwind CSS configuration.

frontend/tsconfig.node.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "composite": true,
+    "skipLibCheck": true,
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "allowSyntheticDefaultImports": true
+  },
+  "include": ["vite.config.ts"]
+}