feat: implement InternshipStatus enum

backend/app/Enums/InternshipStatus.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Enums;
+
+enum InternshipStatus: string
+{
+    case SUBMITTED = 'SUBMITTED';
+
+    case CONFIRMED_BY_COMPANY = 'CONFIRMED_BY_COMPANY';
+    case CONFIRMED_BY_ADMIN = 'CONFIRMED_BY_ADMIN';
+
+    case DENIED_BY_COMPANY = 'DENIED_BY_COMPANY';
+    case DENIED_BY_ADMIN = 'DENIED_BY_ADMIN';
+
+    case DEFENDED = 'DEFENDED';
+    case NOT_DEFENDED = 'NOT_DEFENDED';
+
+    public static function all(): array
+    {
+        return array_map(fn($case) => $case->value, self::cases());
+    }
+}