Redirect legacy /q/* URLs to canonical ladl.link addresses.

External /q requests 301/307 to ladl.link; internal X-Ladill-Internal requests still serve content for platform proxying.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Http/Middleware/RedirectLegacyQrToLadillLink.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use App\Support\LadillLink;
+use Closure;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class RedirectLegacyQrToLadillLink
+{
+    public function handle(Request $request, Closure $next): Response
+    {
+        if (! preg_match('#^q/[a-z0-9]#i', ltrim($request->path(), '/'))) {
+            return $next($request);
+        }
+
+        if (LadillLink::isInternalRequest($request)) {
+            return $next($request);
+        }
+
+        return LadillLink::legacyRedirect($request);
+    }
+}

app/Support/LadillLink.php

@@ -2,11 +2,16 @@
 
 namespace App\Support;
 
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+
 /**
  * Canonical short-link URLs for the Ladill platform (ladl.link).
  */
 final class LadillLink
 {
+    public const INTERNAL_HEADER = 'X-Ladill-Internal';
+
     public static function baseUrl(): string
     {
         $domain = (string) config('link.public_domain', 'ladl.link');
@@ -23,4 +28,33 @@ final class LadillLink
     {
         return self::url($slug).'/'.ltrim($suffix, '/');
     }
+
+    public static function isInternalRequest(Request $request): bool
+    {
+        return $request->header(self::INTERNAL_HEADER) === '1';
+    }
+
+    public static function legacyRedirect(Request $request): RedirectResponse
+    {
+        $shortCode = $request->route('shortCode');
+        if (! is_string($shortCode) || $shortCode === '') {
+            abort(404);
+        }
+
+        $path = ltrim($request->path(), '/');
+        $prefix = 'q/'.$shortCode;
+        $suffix = '';
+        if ($path !== $prefix && str_starts_with($path, $prefix.'/')) {
+            $suffix = substr($path, strlen($prefix) + 1);
+        }
+
+        $target = $suffix === '' ? self::url($shortCode) : self::path($shortCode, $suffix);
+        if ($qs = $request->getQueryString()) {
+            $target .= '?'.$qs;
+        }
+
+        $status = in_array($request->method(), ['GET', 'HEAD'], true) ? 301 : 307;
+
+        return redirect()->away($target, $status);
+    }
 }