feat: add withdraw request functionality and UI components

app/Models/Document.php

@@ -56,6 +56,11 @@ class Document extends Model
         return $this->belongsTo(User::class);
     }
 
+    public function invoice()
+    {
+        return $this->hasOne(Invoice::class);
+    }
+
     public function assignments()
     {
         return $this->hasMany(DocumentAssignment::class);