Add font-features-* utility for font-feature-settings

[adamwathan]

Summary

This PR adds a new font-features-* utility that sets the font-feature-settings CSS property. This is an arbitrary-value-only utility, meaning it does not accept bare values from the theme — only arbitrary values like font-features-["smcp"] or font-features-[var(--features)].

Changes

1. property-order.ts: Added font-feature-settings to the property ordering list, sorted directly after font-family to ensure consistent cascade ordering
2. utilities.ts: Registered the font-features functional utility that emits font-feature-settings
3. utilities.test.ts: Added test coverage including literal values, comma-separated lists, theme references, and expressions
4. CHANGELOG.md: Added entry for the new utility
   Test plan
   All changes are covered by unit tests in utilities.test.ts verifying correct CSS output generation for various value types (literals, comma-separated lists, theme references, and expressions).

https://claude.ai/code/session_01EAccbTHJ9dTUJ53ttq2jc4

[coderabbitai]

Walkthrough

Adds 'font-feature-settings' to the property order in packages/tailwindcss/src/property-order.ts; registers a font-features functional utility that emits font-feature-settings in packages/tailwindcss/src/utilities.ts (the registration is inserted twice); adds tests in packages/tailwindcss/src/utilities.test.ts covering font-features-* with literals, arrays/comma lists, theme references, parentheses, and arbitrary values; and updates CHANGELOG.md to include the new font-features-* utility.

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding a new font-features-* utility for font-feature-settings CSS property.
Description check	✅ Passed	The description is directly related to the changeset, explaining the new utility, its behavior, and placement in property order.

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