Initial upload of BB-Apartment 2026 website.

Adds the complete Next.js website including i18n routing, house and
apartment pages, Beds24 v2 integration for live availability/pricing,
Stripe checkout, contact forms, Docker setup and deployment docs.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/api/portal-session/route.ts

@@ -0,0 +1,44 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getStripe } from "@/src/lib/stripe";
+import { prisma } from "@/src/lib/prisma";
+
+export const dynamic = "force-dynamic";
+
+export async function POST(request: NextRequest) {
+  try {
+    const { bookingReference, email } = await request.json();
+
+    if (!bookingReference || !email) {
+      return NextResponse.json(
+        { error: "Missing bookingReference or email" },
+        { status: 400 }
+      );
+    }
+
+    const booking = await prisma.booking.findUnique({
+      where: { bookingReference },
+    });
+
+    if (!booking || booking.guestEmail !== email || !booking.stripeCustomerId) {
+      return NextResponse.json(
+        { error: "Booking not found" },
+        { status: 404 }
+      );
+    }
+
+    const stripe = getStripe(booking.houseId);
+
+    const session = await stripe.billingPortal.sessions.create({
+      customer: booking.stripeCustomerId,
+      return_url: `${process.env.NEXT_PUBLIC_BASE_URL}/de`,
+    });
+
+    return NextResponse.json({ url: session.url });
+  } catch (error) {
+    console.error("Portal session error:", error);
+    return NextResponse.json(
+      { error: "Failed to create portal session" },
+      { status: 500 }
+    );
+  }
+}