refactor: align codebase with EventCrew domain and trim legacy band stack

- Update API: events, users, policies, routes, resources, migrations
- Remove deprecated models/resources (customers, setlists, invitations, etc.)
- Refresh admin app and docs; remove apps/band

Made-with: Cursor

api/database/factories/OrganisationFactory.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Models\Organisation;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<Organisation> */
+final class OrganisationFactory extends Factory
+{
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        $name = fake()->unique()->company();
+
+        return [
+            'name' => $name,
+            'slug' => str($name)->slug()->toString(),
+            'billing_status' => 'active',
+            'settings' => [],
+        ];
+    }
+}