refactor: create models, factories, and seeders for Company, Internship, InternshipStatus, and StudentData

backend/app/Models/Internship.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class Internship extends Model
+{
+    /** @use HasFactory<\Database\Factories\InternshipFactory> */
+    use HasFactory;
+
+    /**
+     * The attributes that are mass assignable.
+     *
+     * @var list<string>
+     */
+    protected $fillable = [
+        'user_id',
+        'company_id',
+        'start',
+        'end',
+        'year_of_study',
+        'semester',
+        'position_description',
+        'agreement',
+    ];
+}