chore(db): back up email templates before redesign

Store the original template subjects and bodies as restore scripts so the redesigned notifications can be reverted against DD_ECM if needed.

EnvelopeGenerator.Server/EmailTemplateBackups/DocumentRejected_REC_original.sql

@@ -0,0 +1,11 @@
+-- Original email template: DocumentRejected_REC (GUID 9)
+-- Backed up before redesign: 2026-10-29 16:34:21
+-- Subject: ''[DOCUMENT_TITLE]'' - Bestätigung der Ablehnung
+-- Restore by running this script against DD_ECM:
+UPDATE dbo.TBSIG_EMAIL_TEMPLATE
+SET BODY = N'Guten Tag [NAME_RECEIVER],
+<p>Hiermit bestätigen wir Ihnen die Ablehnung des Vorgangs <B><I>''[DOCUMENT_TITLE]''</I></B>!<p>Der Absender <B><I>[NAME_SENDER]</I></B> wurde über die Ablehnung informiert. <p> 
+Mit freundlichen Grüßen<br />
+<br />
+[NAME_PORTAL]'
+WHERE GUID = 9;