chore: remove lock files and ignore them going forward

Lock files contain internal registry URLs that don't work for external consumers of these example apps.

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

Author: likawka

.gitignore

@@ -40,3 +40,8 @@ devspace.yaml
 
 # Environment variables
 .env
+
+# Lock files (not useful for external consumers)
+package-lock.json
+yarn.lock
+pnpm-lock.yaml