chore: track composer.lock, unignore it in .gitignore

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

Author: Vitexus

.gitignore

@@ -14,7 +14,6 @@
 # You may choose to ignore a library lock file http://getcomposer.org/doc/02-libraries.md#lock-file
 # composer.lock
 /nbproject/private/
-/composer.lock
 /.phpunit.result.cache
 /.phpdoc/
 /.build/