Add internal redirect short links (/r/<code>)

A static short link — e.g. printed on a QR code — that resolves to a
Payload-editable internal target path, so the link itself never needs
reprinting when the underlying content moves. Tracks a click count.

app/r/[code]/route.ts

@@ -0,0 +1,21 @@
+import { redirect, notFound } from "next/navigation";
+import { NextRequest } from "next/server";
+import { resolveAndTrackRedirect } from "../../lib/payload";
+
+// A static short link (e.g. printed on a QR code) that always resolves to
+// whatever `targetPath` is currently set on the matching Redirects document
+// in Payload — the QR code itself never needs reprinting when the target
+// changes. `redirect()` (not permanentRedirect()) issues a 307, deliberately
+// non-cacheable client-side since the target can change at any time.
+export async function GET(_request: NextRequest, { params }: { params: Promise<{ code: string }> }) {
+  const { code } = await params;
+  const targetPath = await resolveAndTrackRedirect(code);
+
+  // Defense in depth — Redirects.targetPath is already validated in Payload
+  // to start with "/", same open-redirect guard as api/preview/route.ts.
+  if (!targetPath || !targetPath.startsWith("/") || targetPath.startsWith("//")) {
+    notFound();
+  }
+
+  redirect(targetPath);
+}