Auto-inlog opent in nieuw tabblad via GET route

Vervangt server action door /api/auto-login GET route zodat
<a target="_blank"> werkt. Server action verwijderd.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/auto-login/route.ts

@@ -0,0 +1,28 @@
+import { NextRequest, NextResponse } from "next/server";
+import { createHmac } from "crypto";
+import { getSession } from "../../../lib/auth";
+import { getPlatformDb } from "../../../lib/platform-db";
+
+export async function GET(request: NextRequest) {
+  const session = await getSession();
+  if (!session) return NextResponse.redirect(new URL("/login", request.url));
+
+  const accountId = Number(request.nextUrl.searchParams.get("account_id"));
+  const slug = request.nextUrl.searchParams.get("slug");
+  if (!accountId || !slug) return NextResponse.redirect(new URL("/tenants", request.url));
+
+  const db = getPlatformDb();
+  const user = db
+    .prepare("SELECT id FROM users WHERE account_id = ? AND role = 'admin' LIMIT 1")
+    .get(accountId) as { id: number } | undefined;
+
+  if (!user) return NextResponse.redirect(new URL("/tenants?error=no-admin", request.url));
+
+  const secret = process.env.AUTO_LOGIN_SECRET!;
+  const expires = Date.now() + 60_000;
+  const payload = `${user.id}:${accountId}:${expires}`;
+  const sig = createHmac("sha256", secret).update(payload).digest("hex");
+  const token = encodeURIComponent(`${payload}:${sig}`);
+
+  return NextResponse.redirect(`https://${slug}.rikxplatform.nl/auto-login?token=${token}`);
+}