Add composer.lock to gitignore and remove from repository

Libraries should not commit composer.lock to allow consuming applications to resolve dependencies flexibly.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: JanTvrdik

.gitignore

@@ -3,3 +3,4 @@
 !/cache/.gitkeep
 /.idea
 /phpstan.neon
+composer.lock