Migrate backend to Porto architecture and fix minor bugs

- Fully transitioned the backend to the Porto architectural pattern
- Improved code organization and maintainability
- Fixed minor bugs and inconsistencies

app/Containers/Education/Models/AdmissionCampaign.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Containers\Education\Models;
+
+use App\Ship\Models\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\HasManyThrough;
+
+class AdmissionCampaign extends Model
+{
+    use HasFactory;
+
+    protected $guarded = false;
+
+    protected $casts = [
+      'info' => 'array'
+    ];
+
+    public function admission_plans(): HasMany
+    {
+        return $this->hasMany(AdmissionPlan::class, 'admission_campaigns_id', 'id');
+    }
+
+    public function educationalPrograms(): HasManyThrough
+    {
+        return $this->hasManyThrough(
+            EducationalProgram::class,
+            AdmissionPlan::class,
+            'admission_campaigns_id', // внешний ключ в AdmissionPlan
+            'id',                     // внешний ключ в EducationalPrograms
+            'id',                     // локальный ключ в AdmissionCampaign
+            'educational_programs_id' // локальный ключ в AdmissionPlan
+        );
+    }
+}