Validate and update links (STF-557)

[oschwald]

Adds a lychee link-checker configuration and a
Links GitHub Actions workflow, then fixes the stale and redirecting links it
surfaced. lychee is pinned via mise (mise.toml / mise.lock) so CI and local
runs use the same version, and the workflow installs only lychee (not the full
toolchain). It runs on push, pull request, and weekly to catch external link rot.

max_redirects = 0, so any link that has moved is reported and updated to its
canonical destination.

Link changes (old -> new)

• dev.maxmind.com/minfraud/api-documentation?lang=en -> .../api-documentation/?lang=en (src/MinFraud.php)
• dev.maxmind.com/minfraud/api-documentation/requests?lang=en#... -> .../requests/?lang=en#... (src/MinFraud.php, 9 anchors)
• #schema--request--shopping-cart--item -> #schema--request--shopping-cart (src/MinFraud.php — the --item anchor no longer exists)
• dev.maxmind.com/minfraud/track-devices?lang=en -> .../track-devices/?lang=en (src/MinFraud/Model/Device.php)
• dev.maxmind.com/minfraud/report-transaction/ (404) -> .../report-a-transaction/ (README.md, CLAUDE.md)
• php.net/manual/en/book.phar.php -> www.php.net/manual/en/book.phar.php (README.md)
• php.net/manual/en/book.curl.php -> www.php.net/manual/en/book.curl.php (README.md)
• www.maxmind.com/en/support -> support.maxmind.com/knowledge-base (README.md)
• support.maxmind.com/hc/en-us/articles/5452293435675-Order-and-Shopping-Cart-Inputs#... -> support.maxmind.com/knowledge-base/articles/order-and-shopping-cart-inputs-minfraud (src/MinFraud.php)

Notes

• The minFraud API responses doc renders its schema anchors client-side, so
  lychee cannot verify the #schema--response--risk-score-reason--multiplier-reason
  fragment used in Reason.php even though the page and anchor exist. That
  responses-page fragment is excluded in lychee.toml as a false positive; the
  link itself is unchanged.
• Historical CHANGELOG.md entries are intentionally left unchanged (and excluded
  from scanning).
• Final lychee result: 32 OK, 0 errors, 4 excluded.

Part of STF-557.

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request configures the Lychee link checker by adding a configuration file, updating the mise toolset, and adding a link-checking task. It also updates several outdated or redirected documentation URLs across markdown files and PHP source code comments to ensure correct linking. No review comments were provided, so there is no additional feedback to address.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.