fix(preview-server): detect hsl/hsla colors in compatibility checker

[mvanhorn]

Summary

The email compatibility checker now flags hsl() and hsla() color values as unsupported in Microsoft Outlook on Windows.

Previously, these color functions were invisible to the checker because caniemail.com does not track hsl/hsla support data. Users would unknowingly use hsl colors that render correctly in the preview but fail silently in Outlook (Word rendering engine).

Fixes #2947

Changes

• New file: caniemail-supplemental-data.ts - Contains manually curated support entries for hsl() and hsla() with Outlook Windows marked as unsupported ("n"). Kept separate from the auto-generated caniemail-data.ts so entries survive re-runs of fill-caniemail-data.mts.
• Modified: check-compatibility.ts - Merges supplemental entries with the caniemail data so the existing CSS function matching logic picks up hsl/hsla automatically.

Why a separate file?

The caniemail-data.ts file is auto-generated from caniemail.com's API via fill-caniemail-data.mts. Adding entries directly would get wiped on the next refresh. The supplemental file can be removed once caniemail.com adds official hsl/hsla tracking.

This contribution was developed with AI assistance (Claude Code).

---

Summary by cubic

Flags hsl() and hsla() colors as unsupported in Outlook on Windows in the email compatibility checker to prevent silent rendering failures. Fixes Linear issue #2947 and publishes a patch to @react-email/preview-server.

• Bug Fixes
  • Added supplemental hsl()/hsla() support data and merged it with caniemail so the existing CSS function detection flags these colors for Outlook on Windows.
  • Added a changeset to release this as a patch.

^{Written for commit f27e60b. Summary will update on new commits. Review in cubic}

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npm i https://pkg.pr.new/@react-email/preview-server@3061

commit: f7fd6c5

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

[gabrielmfern]

Thank you!

[gabrielmfern]

Apparently we merged another pull request that was basically a copy of this 🙁 #3401. So sorry for that, but I'm going to close this now since we've already merged the other one.