Add fallback for missing plannedDurationSeconds

Store planned session duration and fix update URL

Update CURRENT_VERSION to 2.6.0

Release Winter Arc season and dual currency system

Add permanent site blocking and improve session handling

Add permanent site blocking to dashboard

Remove daily login reward modal and update season features

Update settings.js

Update social.html

Add auth check and seasonal UI logic to dashboard and social

Add environment configuration module

Add Season 2 features and update UI for Winter Arc

Update register.js

Update popup.js

Update login.js