- New Settings screen (press 'x') for configuring app settings
- Settings stored in data/settings.yaml (user-editable)
- Editable fields: team abbrev, season, API URL, API key (masked), theme
- Team validation against database before saving
- Read-only team info display from database (name, sWAR cap, ID)
- Load order: defaults -> .env -> settings.yaml
- Added pyyaml dependency