fix(core): use matchAll instead of exec in findUsedTokenNames (#333)

* fix(core): use `String.prototype.matchAll` instead of `RegExp.prototype.exec` in `findUsedTokenNames`

Replace `RegExp.prototype.exec` with `String.prototype.matchAll` to avoid
potential issues with shared `lastIndex` state on the module-scoped
`TOKEN_CONSUMER_PATTERN` regex. `matchAll` internally copies the regex,
making the function robust against future changes that might interrupt the
loop early.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: add changeset for findUsedTokenNames fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: mizdra

.changeset/fix-regexp-exec.md

@@ -0,0 +1,5 @@
+---
+'@css-modules-kit/core': patch
+---
+
+fix(core): use `matchAll` instead of `exec` in `findUsedTokenNames` to avoid potential `lastIndex` state issues

packages/core/src/util.ts

@@ -43,8 +43,7 @@ const TOKEN_CONSUMER_PATTERN = /styles\.([$_\p{ID_Start}][$\u200c\u200d\p{ID_Con
 
 export function findUsedTokenNames(componentText: string): Set<string> {
   const usedClassNames = new Set<string>();
-  let match;
-  while ((match = TOKEN_CONSUMER_PATTERN.exec(componentText)) !== null) {
+  for (const match of componentText.matchAll(TOKEN_CONSUMER_PATTERN)) {
     usedClassNames.add(match[1]!);
   }
   return usedClassNames;