Fix post-registration 404, add speaker management, and simplify event creation.

Proxy registration transaction paths on Events, add a join button on the
confirmation page, introduce speaker roster management, and replace the QR
design wizard with merchant-style create/show flows.

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

app/Http/Middleware/RedirectLegacyQrToLadillLink.php

@@ -36,7 +36,7 @@ class RedirectLegacyQrToLadillLink
             return $next($request);
         }
 
-        if ($this->servesStoredAsset($request)) {
+        if ($this->servesStoredAsset($request) || $this->servesRegistrationTransaction($request)) {
             return $next($request);
         }
 
@@ -64,4 +64,24 @@ class RedirectLegacyQrToLadillLink
 
         return (bool) preg_match('#^(image/\d+|item-image/\d+/\d+)$#', $suffix);
     }
+
+    private function servesRegistrationTransaction(Request $request): bool
+    {
+        $shortCode = $request->route('shortCode');
+        if (! is_string($shortCode) || $shortCode === '') {
+            return false;
+        }
+
+        $path = ltrim($request->path(), '/');
+        $prefix = 'q/'.$shortCode.'/';
+        if (! str_starts_with($path, $prefix)) {
+            return false;
+        }
+
+        $suffix = substr($path, strlen($prefix));
+
+        return $suffix === 'register'
+            || str_starts_with($suffix, 'register/')
+            || str_starts_with($suffix, 'registered/');
+    }
 }