This update adds optional temporary-rank duration stacking and improves config handling for existing installations.

New

• Added optional duration stacking for temporary ranks
• When enabled, reapplying the same temporary rank adds the remaining time to the new duration
• Example: buying 3x 7d now results in 21d total
• New config option: rankDurationStackingEnabled

Improved

• Missing config entries are now added automatically on startup
• Existing users no longer need to delete or recreate their config.yml just to get new settings

Notes

• rankDurationStackingEnabled is disabled by default to preserve previous behavior
• Set it to true in config.yml if you want temporary ranks to stack