docs: add memory updates section for user instructions

AGENTS.md

@@ -137,6 +137,8 @@ import React from 'react';
 
 6. **Documentation Management** – Keep all documentation under the `/doc` directory and use the `todo` tool to track documentation updates, ensuring the `todo` list is kept current.
 
+7. **Memory Updates** – When a user instructs the agent to remember information, the agent must record the instruction in `@AGENTS.md` (or relevant documentation) to preserve it for future reference.
+
 ---
 
 ## 4. Frequently Used Commands (Quick Reference)