docs: remove redundant security analysis section from ADR 005

Author: claude

docs-site/docs/development/adr/005-ai-powered-changelog-generation.md

@@ -47,11 +47,6 @@ Additionally, writing changelog entries manually when preparing releases is:
 - Validated industry-standard workflow pattern
 - Confirmed secure implementation without script injection vulnerabilities
 
-**Security Analysis**
-- Identified and fixed script injection vulnerabilities
-- Implemented PATH isolation to prevent command injection
-- Used `actions/github-script@v7` instead of bash interpolation
-
 ## Decision
 
 **We will implement an AI-powered changelog system using Google's Gemini API to automatically generate one-line changelog entries for each PR.**