docs: update changelog for Jan v0.7.2

[Minh141120]

This pull request adds a changelog entry for the Jan v0.7.2 release, highlighting a critical security update and stability verification. The main focus is on updating the happy-dom dependency to address a sandbox vulnerability, with no new features introduced.

Security improvements:

• Added a changelog page 2025-10-16-jan-security-update.mdx documenting the update of happy-dom to version 20.0.0, which prevents untrusted JavaScript from accessing process-level functions and executing arbitrary code outside the sandbox.

Stability assurance:

• Verified stability of the update across macOS, Windows, and Linux, and confirmed that no behavioral changes are introduced.

[Copilot]

Pull Request Overview

This PR documents the security update for Jan v0.7.2, which addresses a critical sandbox vulnerability in the happy-dom dependency by upgrading it to version 20.0.0.

Key Changes:

• Added changelog documentation for the v0.7.2 security release
• Documented the happy-dom upgrade to v20.0.0 and its security implications
• Confirmed cross-platform stability with no behavioral changes

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[github-actions]

Preview URL: https://81f51943.docs-9ba.pages.dev

[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}