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/database/factories/ShiftFactory.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Models\FestivalSection;
+use App\Models\Shift;
+use App\Models\TimeSlot;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<Shift> */
+final class ShiftFactory extends Factory
+{
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        return [
+            'festival_section_id' => FestivalSection::factory(),
+            'time_slot_id' => TimeSlot::factory(),
+            'title' => fake()->randomElement([
+                'Tapper',
+                'Tussenbuffet',
+                'Barhoofd',
+                'Stage Manager',
+                'Stagehand',
+                'Coördinator',
+                'Runner',
+            ]),
+            'slots_total' => fake()->numberBetween(1, 10),
+            'slots_open_for_claiming' => 0,
+            'status' => 'draft',
+            'is_lead_role' => false,
+            'allow_overlap' => false,
+        ];
+    }
+
+    public function open(): static
+    {
+        return $this->state(fn () => ['status' => 'open']);
+    }
+
+    public function withClaiming(int $slots): static
+    {
+        return $this->state(fn () => ['slots_open_for_claiming' => $slots]);
+    }
+
+    public function allowOverlap(): static
+    {
+        return $this->state(fn () => ['allow_overlap' => true]);
+    }
+}