feat: frontend member management

- Leden pagina met VDataTable, rol chips, uitnodigingen sectie
- InviteMemberDialog + EditMemberRoleDialog
- Publieke acceptatiepagina /invitations/[token]
- Router guard uitgebreid met requiresAuth: false support
- MemberCollection backend uitgebreid met volledige pending_invitations lijst

api/database/migrations/2026_04_08_320000_fix_activity_log_morphs_to_ulid.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('activity_log', function (Blueprint $table) {
+            $table->string('subject_id', 26)->nullable()->change();
+            $table->string('causer_id', 26)->nullable()->change();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('activity_log', function (Blueprint $table) {
+            $table->unsignedBigInteger('subject_id')->nullable()->change();
+            $table->unsignedBigInteger('causer_id')->nullable()->change();
+        });
+    }
+};