Add ai-usage metadata tag to modified documentation files

Author: VanMSFT

docs/relational-databases/database-mail/database-mail.md

@@ -6,6 +6,7 @@ ms.author: wiassaf
 ms.date: 11/21/2025
 ms.service: sql
 ms.topic: conceptual
+ai-usage: ai-assisted
 helpviewer_keywords:
   - "architecture [SQL Server], Database Mail"
   - "Database Mail [SQL Server], architecture"

docs/relational-databases/security/networking/tds-8.md

@@ -10,6 +10,7 @@ ms.subservice: security
 ms.topic: conceptual
 ms.custom:
   - ignite-2025
+ai-usage: ai-assisted
 monikerRange: ">=sql-server-ver16 || >=sql-server-linux-ver16 || =azuresqldb-current || =azuresqldb-mi-current || =fabric-sqldb"
 ---