fix: route `lastversion wordpress` to WordPress.org core API

The GitHub adapter returned stale version (6.3.8) because old-branch
security patches pushed the latest 6.9.x tags past the Atom feed's
first page. Now the `wordpress` short name is claimed by the WordPress
adapter and resolved via the version-check API.

Closes the wrong-version issue for WordPress core while keeping plugin
lookups unchanged.

Release 3.6.8

Version 3.6.7: Simplified file-based locking

Changed:
- Lock is now a simple file containing the PID (not a directory with pid file)
- Uses atomic O_CREAT | O_EXCL for race-free lock acquisition
- Backward compatible: automatically cleans up old directory-based locks

Version 3.6.6: Robust stale lock cleanup

Fixed:
- Use shutil.rmtree() instead of os.rmdir() to handle non-empty lock directories
- Old lock directories from pre-v3.6.5 versions are now properly cleaned up
- Added debug logging to aid troubleshooting lock issues

Version 3.6.5: PID-based stale lock detection

Fixed:
- Fixed stale lock files causing LockAcquireTimeout errors after process crashes
- Cache locking now uses PID-based detection instead of simple directory locks
- When a process crashes/is killed, subsequent runs automatically clean up stale locks
- No more manual intervention needed to clear ~/.cache/lastversion/*.lock directories

lastversion 3.6.4

Fix wrong version returned for OpenSSL 3.5 LTS (#218)