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/Models/Shift.php

@@ -0,0 +1,124 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Casts\Attribute;
+use Illuminate\Database\Eloquent\Concerns\HasUlids;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+final class Shift extends Model
+{
+    use HasFactory;
+    use HasUlids;
+    use SoftDeletes;
+
+    protected $fillable = [
+        'festival_section_id',
+        'time_slot_id',
+        'location_id',
+        'title',
+        'description',
+        'instructions',
+        'coordinator_notes',
+        'slots_total',
+        'slots_open_for_claiming',
+        'is_lead_role',
+        'report_time',
+        'actual_start_time',
+        'actual_end_time',
+        'end_date',
+        'allow_overlap',
+        'assigned_crew_id',
+        'events_during_shift',
+        'status',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'is_lead_role' => 'boolean',
+            'allow_overlap' => 'boolean',
+            'events_during_shift' => 'array',
+            'slots_total' => 'integer',
+            'slots_open_for_claiming' => 'integer',
+        ];
+    }
+
+    public function festivalSection(): BelongsTo
+    {
+        return $this->belongsTo(FestivalSection::class);
+    }
+
+    public function timeSlot(): BelongsTo
+    {
+        return $this->belongsTo(TimeSlot::class);
+    }
+
+    public function location(): BelongsTo
+    {
+        return $this->belongsTo(Location::class);
+    }
+
+    public function assignedCrew(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'assigned_crew_id');
+    }
+
+    public function shiftAssignments(): HasMany
+    {
+        return $this->hasMany(ShiftAssignment::class);
+    }
+
+    public function waitlist(): HasMany
+    {
+        return $this->hasMany(ShiftWaitlist::class);
+    }
+
+    protected function effectiveStartTime(): Attribute
+    {
+        return Attribute::get(fn () => $this->actual_start_time ?? $this->timeSlot?->start_time);
+    }
+
+    protected function effectiveEndTime(): Attribute
+    {
+        return Attribute::get(fn () => $this->actual_end_time ?? $this->timeSlot?->end_time);
+    }
+
+    protected function filledSlots(): Attribute
+    {
+        return Attribute::get(fn () => $this->shiftAssignments()->where('status', 'approved')->count());
+    }
+
+    protected function fillRate(): Attribute
+    {
+        return Attribute::get(function () {
+            if ($this->slots_total === 0) {
+                return 0;
+            }
+
+            return round($this->filled_slots / $this->slots_total, 2);
+        });
+    }
+
+    public function scopeOpen(Builder $query): Builder
+    {
+        return $query->where('status', 'open');
+    }
+
+    public function scopeDraft(Builder $query): Builder
+    {
+        return $query->where('status', 'draft');
+    }
+
+    public function scopeFull(Builder $query): Builder
+    {
+        return $query->where('status', 'full');
+    }
+}