feat(content): add GLPI 11.0.11 security release blog post

[eduardofraga]

Summary

• Author comprehensive blog posts for GLPI 11.0.11 in Portuguese (content/pt-br/blog/glpi-11-0-11/index.md) and English (content/en/blog/glpi-11-0-11/index.md).
• Detail why GLPI 11.0.11 supersedes 11.0.10 (fixes critical plugin system regression).
• Break down the 6 High-severity and 2 Medium-severity security vulnerabilities patched.
• Cover EF-TECH release improvements: custom Nginx config templates with IPv6 listener toggle (PR #209), base image upgrade to 11.0.11 (PR #211), and native MySQL/MariaDB SSL/TLS support (PR #207).
• Include deployment guides for Helm (eftech/glpi) and Docker (ghcr.io/eftechcombr/glpi:11.0.11).
• Generate and publish high-resolution 1200x630 cover PNG images across bundles and static assets.
• Cross-link in .context/docs/README.md and .context/agents/README.md.
• Validated via hugo --gc --minify and lychee link checker with 0 errors.