Initial commit: Kalendartool (Next.js, Prisma, Docker)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/layout.tsx

@@ -0,0 +1,29 @@
+/**
+ * Root-Layout (plan.md Abschnitt 13).
+ */
+import type { Metadata } from 'next';
+import './globals.css';
+
+export const metadata: Metadata = {
+  title: 'Kalendartool',
+  description: 'Einfaches Kalender- und Reservierungstool',
+};
+
+export default function RootLayout({
+  children,
+}: Readonly<{ children: React.ReactNode }>) {
+  return (
+    <html lang="de" suppressHydrationWarning>
+      <head>
+        {/* Theme vor dem ersten Paint anwenden, damit kein heller
+            Flash im Dark-Mode sichtbar ist. */}
+        <script
+          dangerouslySetInnerHTML={{
+            __html: `(function(){try{var t=localStorage.getItem('calendar-theme');var d=window.matchMedia('(prefers-color-scheme: dark)').matches;if(t==='dark'||(!t&&d)){document.documentElement.classList.add('dark');}}catch(e){}})();`,
+          }}
+        />
+      </head>
+      <body>{children}</body>
+    </html>
+  );
+}