Introduces a settings reset subcommand with choices so admins can clear one guild override at a time via MongoDB $unset, with live player sync for volume and duplicate-track defaults. Adds settings.actions.resetDone across language files and optional reset aliases (restore, defaults) in settings examples.
Standardized playlist link validation messages across all language files and code, removing specific references to Spotify and YouTube. Updated README and help view to reflect broader platform support and clarified instructions. Removed unused YouTube regex and related thumbnail logic from objects.py.
