Remove unnecessary $model property from factories

Applies patch 3/21 from pixelfed-staging PR #9: removes the redundant
protected $model property from 5 factories (Laravel resolves the model
from the factory name). Unused imports dropped via Pint. Verified
factories still resolve their models and affected tests pass.

database/factories/ActivityFactory.php

@@ -2,14 +2,11 @@
 
 namespace Database\Factories;
 
-use App\Models\Activity;
 use App\Models\Profile;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
 class ActivityFactory extends Factory
 {
-    protected $model = Activity::class;
-
     public function definition(): array
     {
         return [

database/factories/FollowerFactory.php

@@ -2,14 +2,11 @@
 
 namespace Database\Factories;
 
-use App\Models\Follower;
 use App\Models\Profile;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
 class FollowerFactory extends Factory
 {
-    protected $model = Follower::class;
-
     public function definition(): array
     {
         return [

database/factories/ProfileFactory.php

@@ -2,14 +2,11 @@
 
 namespace Database\Factories;
 
-use App\Models\Profile;
 use App\Models\User;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
 class ProfileFactory extends Factory
 {
-    protected $model = Profile::class;
-
     public function definition(): array
     {
         return [

database/factories/StatusFactory.php

@@ -8,8 +8,6 @@ use Illuminate\Database\Eloquent\Factories\Factory;
 
 class StatusFactory extends Factory
 {
-    protected $model = Status::class;
-
     public function definition(): array
     {
         return [

database/factories/UserFactory.php

@@ -2,15 +2,12 @@
 
 namespace Database\Factories;
 
-use App\Models\User;
 use Illuminate\Database\Eloquent\Factories\Factory;
 use Illuminate\Support\Facades\Hash;
 use Illuminate\Support\Str;
 
 class UserFactory extends Factory
 {
-    protected $model = User::class;
-
     public function definition(): array
     {
         return [