chore(release): bump to v6.0.0 — CAISS-readiness release with compliance, governance, CLI

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/llm-security/.claude-plugin/plugin.json

@@ -1,5 +1,5 @@
 {
   "name": "llm-security",
   "description": "Security scanning, auditing, and threat modeling for Claude Code projects. Detects secrets, validates MCP servers, assesses security posture, and generates threat models aligned with OWASP LLM Top 10.",
-  "version": "5.1.0"
+  "version": "6.0.0"
 }