reorganize and cleanup php server code

server/app/Permission.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Vanguard;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class Permission extends Model
+{
+    use HasFactory;
+
+    protected $table = 'permissions';
+
+    protected $fillable = ['name', 'display_name', 'description'];
+
+    protected $casts = [
+        'removable' => 'boolean'
+    ];
+}