fix(seeder): admin sin factory (funciona con composer install --no-dev)

RolesAndPermissionsSeeder creaba el usuario admin con User::factory()->create(),
que depende de fakerphp/faker (require-dev). En producción, tras
"composer install --no-dev", db:seed reventaba con:
  "Call to undefined function Database\Factories\fake()"

Sustituido por User::firstOrCreate(email, [...]) — idempotente y sin dependencia
de fakerphp/faker. Suite 91 verde.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

database/seeders/RolesAndPermissionsSeeder.php

@@ -36,12 +36,15 @@ class RolesAndPermissionsSeeder extends Seeder
         $cliente = Role::firstOrCreate(['name' => 'Cliente']);
         $cliente->givePermissionTo(['view projects']);
 
-        // Create default admin user
-        $user = User::factory()->create([
-            'name' => 'Admin User',
-            'email' => 'admin@email.com',
-            'password' => bcrypt('password'),
-        ]);
+        // Create default admin user (sin factory: los seeders de sistema no deben
+        // depender de fakerphp/faker, que vive en require-dev).
+        $user = User::firstOrCreate(
+            ['email' => 'admin@email.com'],
+            [
+                'name'     => 'Admin User',
+                'password' => bcrypt('password'),
+            ],
+        );
         $user->assignRole('Admin');
     }
 }