feat: admin editable email templates

addresses #869eg7ptr

src/Config/EmailTextKey.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Config;
+
+/**
+ * The transactional mails whose wording admins may edit.
+ *
+ * A case's value is what ends up in email_text.template_key, so renaming one orphans
+ * the stored override and silently falls back to the default in EmailTextCatalog.
+ */
+enum EmailTextKey: string
+{
+    case APPLICATION_ACCEPTED = 'application_accepted';
+    case APPLICATION_REJECTED = 'application_rejected';
+    case ASSIGNMENT_CALLED_OFF = 'assignment_called_off';
+    case DISPOSITION_CALLED_OFF = 'disposition_called_off';
+    case DOCUMENT_REJECTED = 'document_rejected';
+    case REMINDER_CONTRACT_UPLOAD = 'reminder_contract_upload';
+    case REMINDER_INVOICE_UPLOAD = 'reminder_invoice_upload';
+    case REMINDER_DISPOSITION = 'reminder_disposition';
+}