Refresh date stamp and zip outputs

build.ts stamps the current month/year into AGENTS.md, and the zip
files mtime-rebuild from those. Refreshing here so CI's
no-uncommitted-changes guard passes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

skills/llm-security/AGENTS.md

@@ -2,7 +2,7 @@
 
 **Version 1.0**  
   
-March 2026
+April 2026
 
 > **Note:**  
 > This document is mainly for agents and LLMs to follow when maintaining,