Limit-Status im Upload-Flow anzeigen (Warnbanner + Sperrzustände).

Upload-Fehlercodes auswerten und freundliche Dialoge zeigen.

tests/Feature/Api/Event/PublicEventErrorResponseTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Feature\Api\Event;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class PublicEventErrorResponseTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_invalid_join_token_returns_structured_error(): void
+    {
+        $response = $this->getJson('/api/v1/events/not-a-token/stats');
+
+        $response->assertStatus(404);
+        $response->assertJsonStructure([
+            'error' => ['code', 'title', 'message', 'meta'],
+        ]);
+
+        $response->assertJson([
+            'error' => [
+                'code' => 'invalid_token',
+                'title' => 'Invalid Join Token',
+                'message' => 'The provided join token is invalid.',
+            ],
+        ]);
+
+        $this->assertSame('not-a-token', $response->json('error.meta.token'));
+    }
+}