chore(deps): squizlabs/php_codesniffer を 4系（^4.0）へ更新

PHPCS 4.0.x へ更新。PHPCompatibility（^10.0@dev）と PSR-12 の lint は green を維持。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: uidev1116

composer.json

@@ -20,7 +20,7 @@
     "release:major": "@php scripts/release.php major"
   },
   "require-dev": {
-      "squizlabs/php_codesniffer": "3.*",
+      "squizlabs/php_codesniffer": "^4.0",
       "phpcompatibility/php-compatibility": "^10.0@dev"
   },
   "extra": {