[eslint-plugin] Add columnRule/columns/listStyle/caret shorthand expansion to stylex-valid-shorthands

[abhakat]

Expand columnRule, columns, listStyle, and caret shorthands into their longhand
equivalents. columnRule reuses the existing border-like expansion. listStyle handles the
CSS none keyword correctly (applies to both type and image when unambiguous). columns uses
integer/length disambiguation to determine which value is width vs count.

Stack: 6/7 — depends on #1589

What changed / motivation ?

• columnRule: '1px solid red' → columnRuleWidth + columnRuleStyle + columnRuleColor
• columns: '200px 3' → columnWidth: '200px' + columnCount: '3'
• listStyle: 'disc inside url(bullet.png)' → listStyleType + listStylePosition + listStyleImage
• caret: 'red bar' → caretColor: 'red' + caretShape: 'bar'
• Single values pass through unchanged

Linked PR/Issues

Follow-up to #1553, #1552

Additional Context

Added tests covering: single-value passthrough, multi-value expansion, none handling in
listStyle, auto/integer disambiguation in columns, reversed token order in caret, url() images.

Pre-flight checklist

• I have read the contributing guidelines
  Contribution Guidelines
• Performed a self-review of my code

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
stylex	Skipped		Apr 6, 2026 9:55pm

[github-actions]

workflow: benchmarks/size

Comparison of minified (terser) and compressed (brotli) size results, measured in bytes. Smaller is better.
yarn workspace v1.22.22
yarn run v1.22.22
$ node ./compare.js /tmp/tmp.i7pszqeqBC /tmp/tmp.dDX2gDlsiY

Results	Base	Patch	Ratio
@stylexjs/stylex/lib/cjs/stylex.js
· compressed	1,441	1,441	1.00
· minified	4,386	4,386	1.00
@stylexjs/stylex/lib/cjs/inject.js
· compressed	1,793	1,793	1.00
· minified	4,915	4,915	1.00
benchmarks/size/.build/bundle.js
· compressed	496,650	496,650	1.00
· minified	4,847,840	4,847,840	1.00
benchmarks/size/.build/stylex.css
· compressed	99,653	99,653	1.00
· minified	747,850	747,850	1.00
Done in 0.07s.
Done in 0.30s.

[github-actions]

workflow: benchmarks/perf

Comparison of performance test results, measured in operations per second. Larger is better.
yarn workspace v1.22.22
yarn run v1.22.22
$ node ./compare.js /tmp/tmp.ZR3t7oa7NK /tmp/tmp.GB0c0RyTx4

Results	Base	Patch	Ratio
babel-plugin: stylex.create
· basic create	529	518	0.98	-
· complex create	64	60	0.94	!!
babel-plugin: stylex.createTheme
· basic themes	428	397	0.93	!!
· complex themes	34	32	0.94	!!
Done in 0.08s.
Done in 0.34s.