feat(timetable): factories + ArtistTimetableDevSeeder

Eight factories with named states (Genre, Artist, ArtistContact, Stage,
ArtistEngagement, Performance, AdvanceSection, AdvanceSubmission).

ArtistTimetableDevSeeder hooked into DevSeeder::seedEchtFeesten after
the form-builder showcase. Produces:
- 4 stages (Mainstage, Havana, Stairway, Socialite) with prototype-style
  hex colours
- 4 stages × 3 sub-events = 12 stage_days rows
- 4 genres (Hardstyle, Techno, Indie, Live band)
- 6 master artists, each with one tour-manager ArtistContact
- 12 engagements with status mix (1 Draft, 2 Requested, 3 Option,
  2 Confirmed, 3 Contracted, 1 Cancelled). Two artists have two
  engagements each (different sub-events) — exercises D17 multi-
  engagement-per-artist.
- 13 performances, including one parked (stage_id=null = wachtrij)
  and one B2B pair within 3 minutes on Mainstage Saturday to seed
  the Session 4 frontend B2B detector.

Also fix LogOptions method name across 8 models: dontSubmitEmptyLogs()
→ dontLogEmptyChanges() (Spatie's actual API; surfaced when DevSeeder
ran).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/database/factories/ArtistEngagementFactory.php

@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Enums\Artist\ArtistEngagementStatus;
+use App\Models\Artist;
+use App\Models\ArtistEngagement;
+use App\Models\Event;
+use Illuminate\Database\Eloquent\Factories\Factory;
+use Illuminate\Support\Str;
+
+/** @extends Factory<ArtistEngagement> */
+final class ArtistEngagementFactory extends Factory
+{
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        return [
+            // organisation_id is set by the observer from the artist;
+            // factory leaves it null and lets the observer denormalise.
+            'artist_id' => Artist::factory(),
+            'event_id' => Event::factory(),
+            'booking_status' => ArtistEngagementStatus::Draft,
+            'fee_currency' => 'EUR',
+            'buma_applicable' => true,
+            'buma_percentage' => 7.00,
+            'buma_handled_by' => 'organisation',
+            'vat_applicable' => true,
+            'vat_percentage' => 21.00,
+            'payment_status' => 'none',
+            'crew_count' => 0,
+            'guests_count' => 0,
+            'advancing_completed_count' => 0,
+            'advancing_total_count' => 0,
+        ];
+    }
+
+    public function draft(): static
+    {
+        return $this->state(fn () => ['booking_status' => ArtistEngagementStatus::Draft]);
+    }
+
+    public function requested(): static
+    {
+        return $this->state(fn () => [
+            'booking_status' => ArtistEngagementStatus::Requested,
+            'requested_at' => now(),
+        ]);
+    }
+
+    public function option(): static
+    {
+        return $this->state(fn () => [
+            'booking_status' => ArtistEngagementStatus::Option,
+            'option_expires_at' => now()->addDays(14),
+        ]);
+    }
+
+    public function offered(): static
+    {
+        return $this->state(fn () => ['booking_status' => ArtistEngagementStatus::Offered]);
+    }
+
+    public function confirmed(): static
+    {
+        return $this->state(fn () => ['booking_status' => ArtistEngagementStatus::Confirmed]);
+    }
+
+    public function contracted(): static
+    {
+        return $this->state(fn () => [
+            'booking_status' => ArtistEngagementStatus::Contracted,
+            'fee_amount' => fake()->randomFloat(2, 500, 25000),
+            'portal_token' => (string) Str::ulid(),
+        ]);
+    }
+
+    public function cancelled(): static
+    {
+        return $this->state(fn () => ['booking_status' => ArtistEngagementStatus::Cancelled]);
+    }
+}