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/seeders/RoleSeeder.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Seeders;
+
+use Illuminate\Database\Seeder;
+use Spatie\Permission\Models\Role;
+
+class RoleSeeder extends Seeder
+{
+    public function run(): void
+    {
+        // App-level
+        Role::findOrCreate('super_admin', 'web');
+
+        // Organisation-level
+        Role::findOrCreate('org_admin', 'web');
+        Role::findOrCreate('org_member', 'web');
+
+        // Event-level
+        Role::findOrCreate('event_manager', 'web');
+        Role::findOrCreate('staff_coordinator', 'web');
+        Role::findOrCreate('volunteer_coordinator', 'web');
+    }
+}