- Add ESLint with typescript-eslint for unused code detection
- Fix 33 unused variable/import warnings across codebase
- Remove player_name from leaderboard insert (normalized design)
- Add ensureUserProfile() to upsert user display_name to users table
- Update leaderboard queries to join with users(display_name)
- Add getDisplayName() helper for leaderboard entries
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
