feat: fase 2 backend — crowd types, persons, sections, shifts, invite flow

- Crowd Types + Persons CRUD (73 tests)
- Festival Sections + Time Slots + Shifts CRUD met assign/claim flow (84 tests)
- Invite Flow + Member Management met InvitationService (109 tests)
- Schema v1.6 migraties volledig uitgevoerd
- DevSeeder bijgewerkt met crowd types voor testorganisatie

api/app/Http/Resources/Api/V1/MemberCollection.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Resources\Api\V1;
+
+use App\Models\UserInvitation;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\ResourceCollection;
+
+final class MemberCollection extends ResourceCollection
+{
+    public $collects = MemberResource::class;
+
+    public function toArray(Request $request): array
+    {
+        return [
+            'data' => $this->collection,
+        ];
+    }
+
+    /** @return array<string, mixed> */
+    public function with(Request $request): array
+    {
+        $organisation = $request->route('organisation');
+
+        return [
+            'meta' => [
+                'total_members' => $this->collection->count(),
+                'pending_invitations_count' => UserInvitation::where('organisation_id', $organisation->id)
+                    ->pending()
+                    ->where('expires_at', '>', now())
+                    ->count(),
+            ],
+        ];
+    }
+}