fix(rule-utils): keep -1 out of the tagged pseudo variant sort - #5339

Description

createTaggedPseudoClassMatcher builds the variant sort with

sort: PseudoClassesKeys.indexOf(pseudoName) ?? PseudoClassesColonKeys.indexOf(pseudoName),

indexOf returns -1 on a miss, never null/undefined, so ?? never falls through: the
second lookup is dead code and the -1 is passed on as if it were a real sort index.

The bracket form (group-[...]) and the pseudo var form (group-not-[...]) carry no pseudo
class name at all (pseudoName defaults to ''), so their sort is always -1. Two things
follow:

1. -1 sorts ahead of every utility that has no sort, so those variants are lifted out of the
   alphabetical order a dynamic rule is documented to use ("the output of those matched under a
   single dynamic rule will be sorted alphabetically within the group").
2. -1 is not nullish, so at sort: variantSort ?? metaSort it also replaces the rule's own
   symbols.sort. A rule that orders its own tokens loses that order entirely under an
   arbitrary tagged variant, and since the selectors involved have identical specificity the
   emitted order is what decides the cascade.

Affects group-[...], peer-[...], parent-[...], previous-[...] and the *-not-[...],
*-is-[...], *-where-[...] forms in preset-mini, preset-wind3 and preset-wind4.

Reproduction

preset-wind4, with font-11 font-12 font-13 font-14 font-16 font-17 font-18 font-19 written as
group-[:hover]:font-11, group-[[data-attr]]:font-12, group-[.as-parent_&]:font-13,
group-[.not-parent]:font-14, group-[:hover]/label:font-16, group-[[data-attr]]/label:font-17,
group-[.as-parent_&]/label:font-18, group-[.not-parent]/label:font-19, alongside the plain
font-[system-ui] font-$font-name font-550 font-mono font-sans font-thin (these are already in
test/assets/preset-wind4-targets.ts).

Produced now, all eight arbitrary variants jump to the head of the font- group:

.group:hover .group-\[\:hover\]\:font-11{--un-font-weight:11;font-weight:11;}
.group[data-attr] .group-\[\[data-attr\]\]\:font-12{--un-font-weight:12;font-weight:12;}
...
.font-\[system-ui\]{font-family:system-ui;}
.font-\$font-name{font-family:var(--font-name);}
.font-550{--un-font-weight:550;font-weight:550;}
.font-mono{font-family:var(--font-mono);}

Expected, and what this PR generates, is the alphabetical position inside the group:

.font-\[system-ui\]{font-family:system-ui;}
.font-\$font-name{font-family:var(--font-name);}
.group:hover .group-\[\:hover\]\:font-11{--un-font-weight:11;font-weight:11;}
.group[data-attr] .group-\[\[data-attr\]\]\:font-12{--un-font-weight:12;font-weight:12;}
...
.font-550{--un-font-weight:550;font-weight:550;}
.font-mono{font-family:var(--font-mono);}

The same shift shows up in preset-mini, where it moves two rules of equal specificity past each
other: .group\/label[data-attr] .group-\[\[data-attr\]\]\/label\:font-17 used to be emitted
before .group[data-state=open] .group-data-\[state\=open\]\:font-bold, even though the
alphabetical order of the two selectors puts font-bold first. Both are (0,3,0) and both set
font-weight, so the emitted order is what wins.

Fix

createPseudoClassesAndElements a few lines below already normalises the same lookup
(indexOf to -1 to undefined). This extracts that into getPseudoSortIndex and uses it on
both paths, so a miss yields undefined and the sort falls back to the rule's own value. Known
pseudo class names keep the index they have today.

Tests

Three cases in packages-presets/rule-utils/test/pseudo.test.ts:

• arbitrary tagged pseudo variant order: foo-1, group-hover:foo-2, group-[.on]:foo-3,
  group-not-[.off]:foo-4, peer-[.on]:foo-5 from one dynamic rule. Asserts foo-1 is emitted
  before the three arbitrary variants, and that group-hover still sorts by its pseudo index.
  Fails on main with expected 170 to be less than 106.
• arbitrary tagged pseudo variant keeps the rule sort: one rule whose symbols.sort values are
  the reverse of the tokens' alphabetical order, so the assertion can only pass if the rule sort
  survives the variant. On main the two rules come out alphabetically instead.
• colon-only pseudo class sorts by its own index: pins the PseudoClassesColonKeys branch of
  the shared helper through backdrop:, which exists only in that map.

Two snapshot files (preset-mini-targets.css, preset-wind4-targets.css) move the affected rules
into their alphabetical position; the diff is ordering only, no rule gained, lost or changed a
declaration.

pnpm build && pnpm test: 730 passed, 3 skipped, up from 727 passed, 3 skipped on main, no
other test changed. pnpm typecheck and eslint clean.

Note

#5332 edits the prefix: line directly above the one changed here, so the two will conflict
textually if both land. They are independent fixes and either rebase is a one line resolution.