[HIGH] Bump linkify-it to 5.0.2

[OskarEichler]

Summary

• update the existing linkify-it lockfile entry from 5.0.0 to 5.0.2
• remain within the existing compatible 5.x range
• keep the fix lockfile-only

Security impact

linkify-it 5.0.0 is affected by GHSA-22p9-wv53-3rq4 and GHSA-v245-v573-v5vm. Both allow attacker-controlled text, including mailto input, to cause quadratic scanning and CPU denial of service. Version 5.0.2 contains both fixes.

Test Plan

• yarn install --frozen-lockfile --ignore-scripts
• yarn why linkify-it confirmed 5.0.2
• yarn audit no longer reports linkify-it advisories
• yarn lint-markdown: 39 files, 0 errors
• URL and mailto matching compatibility check
• git diff --check

Changelog:

[INTERNAL] [SECURITY] - Bump linkify-it to 5.0.2.