feat: initial project scaffold

- React 19 + Vite + TailwindCSS frontend
- Express + TypeScript backend API
- PostgreSQL schema and migrations
- Docker Compose orchestration
- Drone CI/CD pipeline
- Pages: Dashboard, Servers, Containers, Services, Logs, Metrics, Settings

frontend/src/components/layout/Layout.tsx

@@ -0,0 +1,17 @@
+import { Outlet } from 'react-router-dom'
+import Sidebar from './Sidebar'
+import Header from './Header'
+
+export default function Layout() {
+  return (
+    <div className="flex h-screen bg-[hsl(222.2_84%_4.9%)] overflow-hidden">
+      <Sidebar />
+      <div className="flex flex-col flex-1 overflow-hidden">
+        <Header />
+        <main className="flex-1 overflow-auto p-6">
+          <Outlet />
+        </main>
+      </div>
+    </div>
+  )
+}