feat: mark a library document for a specific purpose

src/Config/UploadToken.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Config;
+
+/**
+ * The slots in the staff-wide document library (Upload::TYPE_DOCUMENT) that code looks a file up
+ * by, rather than by id or name.
+ *
+ * A fixed list and not free text on purpose: something in the application has to consume a slot
+ * for it to mean anything, so inventing one without a release would only produce a token nothing
+ * reads - and a typo would look exactly the same as a document nobody has assigned yet, while
+ * silently dropping an attachment.
+ *
+ * A case's value is what ends up in upload.token, so renaming one orphans the assignment and the
+ * mail quietly loses its attachment. The column is unique: one document per slot.
+ */
+enum UploadToken: string
+{
+    case APPLICATION_FORM_HANDOUT = 'application_form_handout';
+
+    /**
+     * What the document library offers in its dropdown.
+     */
+    public function label(): string
+    {
+        return match ($this) {
+            self::APPLICATION_FORM_HANDOUT => 'Handout für die 2. Mail an Bewerber:innen',
+        };
+    }
+}