Fix seeder to actually create admin user

Two issues fixed:
1. Changed create() to firstOrCreate() - makes seeder idempotent
   (can run multiple times without 'already exists' errors)

2. Seeder now CREATES admin user instead of just assigning role
   to existing user. Previous code assumed user existed.

Admin credentials:
- Email: admin@example.com
- Password: password

src/database/seeders/RolePermissionSeeder.php

@@ -22,21 +22,27 @@ public function run(): void
         ];
 
         foreach ($permissions as $permission) {
-            Permission::create(['name' => $permission]);
+            Permission::firstOrCreate(['name' => $permission]);
         }
 
-        $adminRole = Role::create(['name' => 'admin']);
+        $adminRole = Role::firstOrCreate(['name' => 'admin']);
         $adminRole->givePermissionTo(Permission::all());
 
-        $editorRole = Role::create(['name' => 'editor']);
+        $editorRole = Role::firstOrCreate(['name' => 'editor']);
         $editorRole->givePermissionTo(['users.view', 'users.edit']);
 
-        $viewerRole = Role::create(['name' => 'viewer']);
+        $viewerRole = Role::firstOrCreate(['name' => 'viewer']);
         $viewerRole->givePermissionTo(['users.view']);
 
-        $admin = User::where('email', 'admin@example.com')->first();
-        if ($admin) {
-            $admin->assignRole('admin');
-        }
+        // Create admin user if not exists
+        $admin = User::firstOrCreate(
+            ['email' => 'admin@example.com'],
+            [
+                'name' => 'Admin',
+                'password' => bcrypt('password'),
+                'email_verified_at' => now(),
+            ]
+        );
+        $admin->assignRole('admin');
     }
 }